redesign of topographic mapping system using unified

Redesign of Topographic Mapping System using Unified Modeling Lan-

guage (UML)

Kwon, Tae – Sub March, 2002

Redesign of Topographic Mapping System using Unified Modeling Language (UML)

by

Kwon, Tae - Sub

Thesis submitted to the International Institute for Geo-Information Science and Earth Observation (ITC) in partial fulfilment of the requirements for the degree of Master of Science in Geo-Information

Management

Degree Assessment Board

Chairman: Dr. M. M. Radwan External examiner: Prof. Dr. Ir. P.van Oosterom Supervisors: Mr. A. M. Tuladhar, MSc. Mr. C. Paresi

INTERNATIONAL INSTITUTE FOR GEO-INFORMATION SCIENCE AND EARTH OBSERVATION

ENSCHEDE, THE NETHERLANDS

Disclaimer This document describes work undertaken as part of a programme of study at the International Institute for Geo-Information Science and Earth Observation. All views and opinions expressed therein remain the sole responsibility of the author, and do not necessarily represent those of the institute.

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Abstract

As the environment surrounding National Mapping Agencies (NMAs) changes over time, they are faced with many challenges. But until recently most NMAs have several problems such as limited number of products and services, non-interoperability of spatial data, inefficient data exploitation within organization and low productivity, each of which causes to lose competitive power. Most NMAs have initiated business process redesign (BPR) project to overcome these problems and im-prove their business. Topographic mapping system as a primary system in NMAs is a first priority in BPR project.

The objective of this research is to redesign topographic mapping system complying with the Open GIS Specification. To achieve this objective many tasks are carried out throughout the thesis. Chapter 1 gave a glance over the research that includes background, research problems, objectives, and meth-odology in brief. Chapter 2 gave detailed description of evolutionary stages of National Mapping Agencies (NMAs) and business driving forces and challenges of NMAs. In addition, this chapter ex-plained new technologies and their advantages on various tasks in NMAs. This chapter contributes to define strategic objective of the system and introduce technological innovation into the system. Chap-ter 3 reviewed literatures about GIS interoperability and object-oriented business process modeling. In first part of this chapter, various spatial data exchange strategies are introduced in conjunction with introduction of the Open GIS Specification. It provided general concept of interoperability and basic understanding of the Open GIS Specification. In second part, object-oriented business process model-ing methodology was explained with basic concept of BPR. In this thesis, use-case driven approach developed by Jacobson I. was introduced because of its wide use in system design and modeling. In chapter 4, conceptual architecture of topographic mapping system was developed in the first part. The proposed system is modeled by object-oriented modeling tool, UML. The proposed architecture con-sists of four main components: production processes component, service delivery processes compo-nent, geodatabase management component, and workflow component. The first two components, pro-duction processes component and service delivery component, are considered as core business proc-esses to be modeled. The proposed system was verified in chapter 5 by checking consistency of mod-els and testing functional requirements of the system with available technologies and sample data. Three different levels of test were carried out in this thesis: unit test, integration test, and system test. Unit and integration test were carried out by checking consistency on unit object and interactions be-tween objects. The assessment questions were introduced as a guideline to assess accuracy of the models. System test was carried out by implementation of the small part of the system. This research proposed how to apply unified modeling language (UML), one of the most powerful object-oriented modeling tools, in BPR project of topographic mapping system. This methodology provides comprehensive and understandable view of the system: external and internal model, static and dynamic model. The model was verified by checking consistency with assessment questions and functional requirements by implementing part of the system with available software and data at pre-sent.

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Acknowledgement During this research period, I received encouragement and assistance from many people to whom I am happy to express my appreciation and gratitude. I would like to express my deepest gratitude to my supervisor, Mr. A. M. Tuladhar, MSc for his encouragement and scientific suggestions to carry out this research. When I could not de-cide the research subject in the beginning of my research, he gave me invaluable advice to de-cide the research subject. He guided me with critical and creative advice throughout the re-search. I am also thankful to my co-supervisor, Mr. C. Paresi who gave me valuable advice and con-structive remarks. His advice was always critical and of value to my research. I appreciate the advice and assistance from Ir. C. Lemmen. He always encouraged me and of-fered me an invaluable advice. Special thank goes to Professor Ir. P. v.d. Molen for his critical questions and suggestions during the mid-term presentation. I would like to express thanks to all my colleagues in GIM.2, Leslie Nkansa Osei-Bonsu, Malin Pholbud, Nina Rutakwamirwa, Rosal Dolanas, and Lupe Chrispin Ochieng from GFM. 2. I thank Korea Army for giving me a chance to study at ITC. This chance gave me a lot of challenges and opportunities. My great thanks must go to my lovely family, Eun-Kyung, Jun-Young, and Sun-Woo. I owed innumerable things to my family. Deep appreciation goes to my family in Korea who did not spare any effort to encourage me. Finally, I would like to dedicate this work to my late father who is in most peaceful place. He gave me mental support when I was in difficulty. I am sure that he would be proud of me and happy to see my family and me.

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Table of Contents

Abstract .......................................................................................................... I

Acknowledgement ....................................................................................... II

Table of Contents ...................................................................................... III

List of Figures ........................................................................................... VII

List of Tables ...............................................................................................IX

List of Appendixes .....................................................................................IX

1. Introduction................................................................................................ 1 1.1. Background ............................................................................................................................. 1 1.2. Research Problem.................................................................................................................... 1 1.3. Research Context .................................................................................................................... 2

1.3.1. Geographic Information Infrastructure (GII) .................................................................. 2 1.3.2. Open GIS Consortium (OGC)......................................................................................... 3 1.3.3. Scope of this research ..................................................................................................... 4

1.4. Research Objectives ................................................................................................................ 5 1.5. Research Questions ................................................................................................................. 5 1.6. Research Methodology............................................................................................................ 6 1.7. Structure of Thesis .................................................................................................................. 6 1.8. Operational Plan...................................................................................................................... 7

2. Evolution and business challenges of topographic mapping system....... 8 2.1. Introduction ............................................................................................................................. 8 2.2. Evolution of topographic mapping system.............................................................................. 8

2.2.1. Mission............................................................................................................................ 8 2.2.2. Products and Services ................................................................................................... 10 2.2.3. Technology development .............................................................................................. 11 2.2.3.1. Data Acquisition........................................................................................................ 11 2.2.3.2. Data Management ..................................................................................................... 14 2.2.3.3. Data Visualization and Distribution.......................................................................... 14

2.3. Work procedure of an example of current production system.............................................. 15 2.4. Business Challenges for change............................................................................................ 20

2.4.1. Key Drivers to change................................................................................................... 20

IV

2.4.1.1. Budget constraint ...................................................................................................... 21 2.4.1.2. New Legislation ........................................................................................................ 22 2.4.1.3. Customers’ Requirements ......................................................................................... 22 2.4.1.4. GIS Market ................................................................................................................ 22 2.4.1.5. Information technology ............................................................................................. 22 2.4.2. Business Challenges...................................................................................................... 23 2.4.2.1. Customer focused...................................................................................................... 23 2.4.2.2. Be ready to changing environment............................................................................ 23 2.4.2.3. Effective use of IT..................................................................................................... 23 2.4.2.4. Provision of various products and services............................................................... 24

2.5. Advantages of New Information Technology (IT)................................................................ 25 2.5.1. Geodesy......................................................................................................................... 25 2.5.2. Photogrammetry ............................................................................................................ 25 2.5.3. Cartography................................................................................................................... 26 2.5.4. Database Management System (DBMS) within GIS context ....................................... 26 2.5.5. Network technology ...................................................................................................... 27

2.6. Concluding Remarks ............................................................................................................. 27

3. GIS interoperability and Object-oriented business process modeling . 29 3.1. Introduction ........................................................................................................................... 29 3.2. GIS Interoperability............................................................................................................... 29

3.2.1. Definition of interoperability in GIS industry............................................................... 29 3.2.2. Geospatial data exchange and access............................................................................ 30 3.2.3. Increasing demand for Enterprise GIS .......................................................................... 31

3.3. The Open GIS Specification (OGIS) .................................................................................... 32 3.3.1. Open GIS Specification (OGIS).................................................................................... 32 3.3.2. Technical foundations for OGIS ................................................................................... 33 3.3.3. Open Geodata Model .................................................................................................... 35

3.4. Business Process Reengineering (BPR)................................................................................ 36 3.4.1. Definition of BPR ......................................................................................................... 36 3.4.2. Object – Oriented Business Engineering: BPR Methodology ...................................... 37 3.4.3. Critical Success Factors (CSFs).................................................................................... 38

3.5. Object-oriented Business Process Modeling using UML..................................................... 39 3.5.1. Use –Case driven Business Process Modeling.............................................................. 39 3.5.2. The Use – Case Model .................................................................................................. 40 3.5.2.1. Identification of Actors ............................................................................................. 40 3.5.2.2. Use-Cases .................................................................................................................. 41 3.5.2.3. An example of the Use-Case Model ......................................................................... 42 3.5.3. Information model......................................................................................................... 42 3.5.3.1. Concept of Business Objects..................................................................................... 42 3.5.3.2. Characteristics of Business Objects .......................................................................... 43 3.5.3.3. Relationships between Objects ................................................................................. 43 3.5.4. The Object Model ......................................................................................................... 43 3.5.4.1. Interaction diagrams.................................................................................................. 43

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3.5.5. Verification of Business model..................................................................................... 44 3.6. Concluding Remarks ............................................................................................................. 44

4. Redesign Topographic Mapping System ................................................ 45 4.1. Introduction ........................................................................................................................... 45 4.2. Proposed System Architecture .............................................................................................. 45

4.2.1. Strategic objectives of topographic mapping system.................................................... 45 4.2.2. Conceptual Architecture of proposed topographic mapping system ............................ 46 4.2.2.1. Production processes................................................................................................. 46 4.2.2.2. Service delivery processes ........................................................................................ 47 4.2.2.3. Geodatabase management ......................................................................................... 47 4.2.2.4. Workflows................................................................................................................. 47

4.3. Business sub-systems for topographic mapping system ....................................................... 47 4.4. Models for production system............................................................................................... 48

4.4.1. Actors and use-case model............................................................................................ 48 4.4.1.1. Identification of actors .............................................................................................. 49 4.4.1.2. Identification of Use-Cases ....................................................................................... 49 4.4.2. Workflow activities: Activity diagram.......................................................................... 50 4.4.2.1. Text description of use-case workflow ..................................................................... 50 4.4.2.2. Activity diagram........................................................................................................ 51 4.4.3. Information model......................................................................................................... 51 4.4.4. Object model ................................................................................................................. 53

4.5. Models of Service delivery system ....................................................................................... 55 4.5.1. Actors and use-case model............................................................................................ 55 4.5.1.1. Identification of use-cases......................................................................................... 55 4.5.2. Workflow activities: Activity diagram.......................................................................... 56 4.5.2.1. Text description of use-case workflow ..................................................................... 56 4.5.2.2. Activity diagram........................................................................................................ 56 4.5.3. Information model......................................................................................................... 57 4.5.4. Object model ................................................................................................................. 57


5. Verification of the proposed system........................................................ 61 5.1. Introduction ........................................................................................................................... 61 5.2. Verification of the models..................................................................................................... 61

5.2.1. Object-oriented modelling life cycle............................................................................. 61 5.2.2. Introduction of Assessment Questions (or Indicators).................................................. 63 5.2.2.1. Assessment Questions for Use Case diagram and Use Case .................................... 63 5.2.2.2. Assessment Questions for Class diagram ................................................................. 64 5.2.2.3. Assessment Questions for Sequence diagram........................................................... 64 5.2.3. ‘Customer demand product delivery’ use-case ............................................................. 64 5.2.3.1. Unit and integration Test........................................................................................... 64 5.2.3.2. Answering to Assessment Questions ........................................................................ 68

5.3. Testing functional requirements of the system ..................................................................... 69 5.3.1. Introduction of Oracle SpatialTM ................................................................................... 69

VI

5.3.1.1. Object – relational DBMS......................................................................................... 69 5.3.1.2. Spatial Data Model.................................................................................................... 70 5.3.1.3. Spatial Index.............................................................................................................. 70 5.3.1.4. Spatial Query............................................................................................................. 70 5.3.2. Create new spatial layer (table) into Topographic database ......................................... 71 5.3.2.1. Spatial data for experiment ....................................................................................... 71 5.3.2.2. Convert data .............................................................................................................. 72 5.3.2.3. Create spatial table .................................................................................................... 72 5.3.2.4. Load spatial data ....................................................................................................... 72 5.3.3. Produce customer demand product with data from Topographic database .................. 73 5.3.3.1. Data access and spatial query by SQL*Plus ............................................................. 73 5.3.3.2. Data access and spatial operation with PCI Geomatica ............................................ 74


6. Conclusions and Recommendations........................................................ 76 6.1. Introduction ........................................................................................................................... 76 6.2. Conclusions ........................................................................................................................... 76 6.3. Recommendations ................................................................................................................. 77

References and bibliography...................................................................... i Appendix ........................................................................................................ I

VII

List of Figures

Figure 1-1 Archtecture of a NGDI (R. Groot & J. McLaughlin, 2000)......................................3

Figure 1-2 Overview of OGIS Architecture (from The OpenGIS Guide) ..................................4

Figure 1-3 Overview of Open GIS environment from NMA point of view...............................5

Figure 2-1 Work procedure of a current topographic production system.................................16

Figure 2-2 Key drivers to change..............................................................................................21

Figure 2-3 Level of cost recovery of OS (from R. Groot & J. McLaughlin, 2000)..................22

Figure 2-4 Diversity of Products (D. Prado, 1998)...................................................................24

Figure 3-1 Interoperability between different GIS (Y. Bishr, 1997) ........................................29

Figure 3-2 Geospatial data exchange and interoperability .......................................................30

Figure 3-3 The role of Open GIS Specification (adopted from OGC, 1998) ...........................32

Figure 3-4 Polygon object in different GIS ..............................................................................34

Figure 3-5 Open GIS Specification (adopted from OGIS topic 12) .........................................35

Figure 3-6 The Open Geodata Model (adopted from OGC) ....................................................36

Figure 3-7 Object-oriented Business Engineering (I. Jacobson, 1994) ....................................37

Figure 3-8 Business Process Architecture ................................................................................39

Figure 3-9 Overview of Object-oriented business process modeling (I. Jacobson, 1994) .......40

Figure 3-10 Actors and System boundary ................................................................................41

Figure 3-11 An example of a Use Case Model.........................................................................42

Figure 4-1 Conceptual Architecture of proposed topographic mapping system ......................46

Figure 4-2 Topographic mapping system and its sub systems..................................................48

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Figure 4-3 Use Case model of production system....................................................................49

Figure 4-4 Activity diagram of Create Topographic DB use case............................................52

Figure 4-5 Information Model of Create Topographic DB use case ........................................53

Figure 4-6 Object Model of Create Topographic DB use case.................................................54

Figure 4-7 Use case model of service delivery system.............................................................55

Figure 4-8 Activity diagram of Customer demand product delivery use case..........................57

Figure 4-9 Information Model of Customer demand product delivery use case ......................58

Figure 4-10 Object Model of Customer demand product delivery use case.............................59

Figure 5-1 Object-oriented modeling life cycle........................................................................62

Figure 5-2 ‘Customer handler’ object with related objects in information model ...................66

Figure 5-3 ‘Customer handler’ object in Object Model ...........................................................67

Figure 5-4 Conceptual framework of functional requirements test ..........................................69

Figure 5-5 Data Model hierarchy of Oracle spatial ..................................................................70

Figure 5-6 Optimized Query Model .........................................................................................71

Figure 5-7 Spatial data loading into Oracle spatial database....................................................71

Figure 5-8 Spatial Query with standard SQL statement ...........................................................74

Figure 5-9 The result of spatial query.......................................................................................74

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List of Tables

Table 2-1 Evolution of Topographic Mapping System ..............................................................9

Table 2-2 Earth Observation Satellite (From Principles of Remote Sensing)..........................11

Table 5-1 CRC card of ‘customer handler’ class......................................................................65

Table 5-2 Assessment Questions to Information model and Object model .............................68

List of Appendixes

Appendix A Unified Modeling Language (UML).......................................................................I

Appendix B Principles of verification, validation, and accreditation of model ..................... VII

Appendix C Spatial Data Loading into Oracle spatial........................................................... VIII

Appendix D Spatial Data for Experiment..................................................................................X

Appendix E Sample product derived from Oracle spatialTM .................................................. XII


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1. Introduction

1.1. Background

As technology evolves, many approaches considered unavailable in early days become possible. For example, people who are geographically apart each other can communicate through the Internet. With hardware development, large geodataset can be stored in a single database. Development of satellite technology leads to new data acquisition possibility. There are many other technological drivers that lead National Mapping Agencies (NMAs) to new business environment. No matter how those changes affect NMAs, it is definite that they are facing with both internal and external challenges. Tradition-ally, the core business of NMAs was producing topographic maps in paper format and still much at-tention is on it. To meet changing demands from diverse GIS users, NMAs have started producing digital topographic maps and database (DB). As a producer of foundation data for a number of GIS users, NMA is pressed by other requirements, that is, to supply not only digital topographic map but also foundation data such as geodetic control, orthoimage, digital elevation model, and geographic names each of which is in turn a component of digital topographic map. All the data mentioned above should be maintained in well-organized manner in order to be accessible for users who need that on time and in suitable format. To keep competitiveness in this business area, NMAs should make them-selves ready to cope with change. One of main problem that most NMAs are confronting is non-interoperability of geodata with their users. This problem is not only for NMAs but also for almost all GIS industry. Therefore GIS users and software developers realized that achieving interoperability of geodata and geoprocessing is the most important step for efficient use of GIS. The Open GIS Consortium (OGC), comprised of a num-ber of leading GIS software vendors, governmental agencies, research institutes, and so on, is a non-profit organization of which main goal is to develop a set of requirements, standards, and specifica-tions which support interoperability. Most software developers are trying to follow OGC specification simply because it guarantees interoperability of their own products. The important agenda of this research is process modeling. In order for organization to be better un-derstood to all involved people, it should be presented in well-defined and understandable way. Proc-ess modeling is the well-known and proven technique in business engineering society. In this research, Unified Modeling Language (UML) is used for process modeling. Although the motive of using UML for redesign of topographic map (DB) production is extensive use in OGC, the advantage of UML is examined in this research.

1.2. Research Problem

National Mapping Agency (NMA) is a national organization of which main objective is to produce topographic maps for the governmental and private sector. The normal standard products are used by a number of different organizations for different purposes. The users require information either in analogue or digital forms according to their applications. As digital technology is introduced, NMA is


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expanding their products to some extent. But whole system of NMA is still remaining in a traditional way that is fit to produce analogue topographic maps. Product diversity is one of the urgent tasks of NMA in order to strengthen competitive power. With digital working environment, a variety of products can be produced and stored in digital form. Each product has its own value to users as well as it is an input for another products. Hence, these products should be organized in well-structured way in order for them to be ready for internal and external use. On the other hand, each of data users has its own application tools that fit their purpose. In most cases, they need to convert original data to the data format which their tools can read and manipulate. During this converting process, the users not only waste time and money but also lose a lot of significant information. If they are using a software tool complying with certain specification and NMA is also providing same specification data, there is no need for data conversion therefore there would not be loss of information and no extra expenditure for data acquisition. There is a promising solution for interoperability problem. As mentioned before, Open GIS Consor-tium (OGC) is devoted to develop specification for geodata and geoprocessing, so called, Open GIS Specification (OGIS). In this research, the OGIS is further discussed in chapter 3 and it is used for standard with which diverse GIS user communities including NMA comply. To make organization understandable, modeling technique is referred to the best solution. The good business model can be used not only for managing current organization but also for reengineering or improving organization. This research focuses on redesigning of business process for topographic map production to comply with Open GIS Specification (OGIS).

1.3. Research Context

1.3.1. Geographic Information Infrastructure (GII)

Geographic Information Infrastructure (GII) is the complex of institutional, organizational, techno-logical, human, and economic resources facilitating the sharing, access to, and responsible use of geo-spatial data at an affordable cost for a specific application domain or enterprise (Groot R. & McLaughlin J., 2000). GII aims to achieve full exploitation of geospatial information within and dif-ferent application domains. Although implementation of GII was strongly affected by development in information technology (IT), GII is also related to institutional, regulatory, and financial elements as mentioned in its definition. The National Geospatial Data Infrastructure (NGDI) seeks to support the sharing of data in the na-tional context by means of a set of standards, such as: national spatial reference systems, a national topographic template, a national elevation model, any other standardized data set of national scope such as geographical names, administrative boundaries, certain thematic data sets (soils, hydrography, vegetation population, etc.), and meta data standards to describe in a consistent manner each of the GDI holdings (Groot R. & McLaughlin J., 2000). Geographic Information Infrastructure is beyond the objective of this research. In this research, GII is not elaborated in more detail. However, clear understanding of GII is basic requirement for solving research problem. Figure 1 – 1 shows how national geospatial data infrastructure works as an intermediary within and between domains.


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Application storage

Clearinghouse Function

Geospatial DataService Centre

(for this domain)Integrity:Harmonization/standardsGDI administration/operationsPolicy implementationOperational:Transformation servicesAdvisory services

InformationPolicy

Direction

GD

SCs for other dom

ains

Framework Data

(Foundation Data)

Real estatemanagement

Physicalplanning

Environmentprotection

Other domainapplication

Domain Applicaiton

Other Data Providers

Administrativeboundary

Transportation

HydrogrphyCadastral dataLand use/cover

Geodetic control

DEM

Orthoimagery

Topographic template

Geographic name

Figure 1-1 Archtecture of a NGDI (Groot R. & McLaughlin J., 2000)

1.3.2. Open GIS Consortium (OGC)

The overall goal of Open GIS Consortium (OGC) is to encourage software developers and integrators to adhere to OGIS in order to make interoperable GIS environment. The Open GIS Specification (OGIS) is a principal product of OGC. The Open GIS Specification provides a framework for soft-ware developers to create software that enables their users to access and process geographic data from a variety of sources. OGIS includes Open Geodata Model, OGIS Information Communities Model, and OGIS Services.

The OpenGIS Specification defines (The OpenGIS Guide, Third Edition, 1998):

Open Geodata Model:

A general and common set of basic geographic information types that can be used to model the geo-data needs of more specific application domains, using object-based and/or conventional program-ming methods.

OpenGIS Services Model:

The set of services needed to 1) access and process the geographic types defined in the Open Geo-data Model and 2) provide capabilities to share geodata within communities of users who use a com-mon set of geographic feature definitions and translate between different communities of users that use different sets of geographic feature definitions.

Information Communities Model:

A way for a community of geodata producers and users who already share a common set of geo-graphic feature definitions to efficiently and effectively maintain these definitions and to catalogue


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and share datasets conforming to these definitions. An efficient and optimally accurate way for differ-ent communities of geodata users and producers to share geodata despite their dissimilar sets of geo-graphic feature definitions.

Figure 1-2 Overview of OGIS Architecture (from The OpenGIS Guide)

1.3.3. Scope of this research

In this research, there are two main subjects are dealt with. Firstly, the OpenGIS Specification is investigated as a common standard in open GIS industry. Secondly, topographic mapping system is redesigned in order to overcome problems that are mentioned in section 1.2 and im-prove the business. For second items, process modeling technique is introduced and applied to redesign business process. Unified Modeling Language (UML) which is one of the most pow-erful object-oriented modeling tools is used in this thesis. Finally, redesigned business process is to be validated by checking consistency between different models and implementing part of the proposed system with currently available software and sample data. Below is the diagram which shows the scope of this research.

Real estate

Management

Physical Planning

Environment Protection

Agriculture Application

Other Domain Application

NMAGeographic InformationInfrastructure

(GII)

Data Acquisition Data

Processing Data

Management

Open GIS Specification

Foundation Data


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Figure 1-3 Overview of Open GIS environment from NMA point of view

1.4. Research Objectives

The main objective of this research is

To redesign Topographic Mapping System that complies with OpenGIS Specification.

In order to achieve the main objective, several sub-objectives have to be achieved. These are listed below.

• To investigate business drivers and challenges to NMAs

• To investigate advantages of advanced Information Technology

• To propose a conceptual architecture of topographic mapping system

• To model the proposed system using UML

• To explore the general approach to validate object-oriented model

• To test the functional requirements of the proposed system

1.5. Research Questions

In order to achieve research objective, following questions need to be addressed. 1. How have NMAs been evolved up to now?

• How has the mission of NMAs been changing?

• What kinds of products and services have they been producing?

• What kinds of information technologies have been used in NMAs?

2. What are the key-factors driving NMAs to dramatic change?

3. What are the business challenges NMAs are facing with?

4. What are the advantages of new information technology to topographic mapping system?

5. What is meant by GIS interoperability?

• How are spatial data exchanged between heterogeneous systems?

• What is the Open GIS Specification and its approach to interoperable spatial data?

6. What is the proposed system architecture of topographic mapping system?

7. What is object-oriented business process modeling?


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• What are the objects in topographic mapping system?

• How to model static and dynamic aspects of topographic mapping system?

8. How to verify the proposed system?

• What methodology exists to check consistency of models in object-oriented modeling?

• What technology is currently available for implementation?

1.6. Research Methodology

Task 1. Analyzing situation.

This task helps to answer question 1, 2, and 3. Comprehensive literature review is carried out in order to investigate and analyze evolutionary stages of National Mapping Agencies (NMAs) and business driving forces and challenges of NMAs.

Task 2. Investigating information technology

This task contributes to answering question 4. New information technologies and their advantages to NMAs are reviewed.

Task 3. Studying GIS interoperability

The purpose of this task is to answer question 5. Various spatial data exchange strategies are intro-duced. The Open GIS Specification is studied focusing on Open Geodata Model.

Task 4. Developing conceptual architecture of topographic mapping system

This task aims to propose conceptual system architecture. Necessary components and their roles in the system are identified.

Task 5. Modeling proposed topographic mapping system

This task aims to answer question 7. Proposed topographic mapping system is modeled by using Uni-fied Modeling Language (UML).

Task 6. Testing the redesigned Topographic Map (DB) Production with Prototype.

This task aims to verify consistency of models and feasibility of the proposed system.

1.7. Structure of Thesis

Chapter 1. Introduction

This chapter gives a glance over the research that includes background, research problems, objectives, and methodology in brief.

Chapter 2. Evolution and business challenges of topographic mapping system

This chapter gives detailed description of evolutionary stages of National Mapping Agencies (NMAs) and business driving forces and challenges of NMAs. In addition, this chapter explains new technolo-gies and their advantages on various tasks in NMAs.

Chapter 3. GIS interoperability and Object-oriented business process modeling


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This chapter reviews literatures about GIS interoperability and object-oriented business process mod-eling. In first part of this chapter, various spatial data exchange strategies are introduced in conjunc-tion with introduction of the Open GIS Specification. In second part, object-oriented business process modeling methodology is explained with basic concept of BPR.

Chapter 4. Redesign topographic mapping system

In this chapter, conceptual architecture of topographic mapping system is developed in first part. The proposed system is modeled by object-oriented modeling tool, UML.

Chapter 5. Verification of the proposed system

The proposed system is verified in this chapter by checking consistency of models and implementa-tion part of the system with available technologies and sample data.

Chapter 6. Conclusions and Recommendations

Conclusions and further Research topics are given.

1.8. Operational Plan

Task Name Sep. 01 Oct. 01 Nov. 01 Dec. 01 Jan. 02 Feb. 02 Mar. 02

Literature Review

Analyze situation

Developing conceptual system architecture

Modeling topographic map-ping system

Verification and Conclusion

Thesis Writing

- Chapter 1

- Chapter 2

- Chapter 3

- Chapter 4

- Chapter 5

- Chapter 6


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2. Evolution and business challenges of topographic mapping system

2.1. Introduction

Topographic maps are the fundamental products of the national mapping agency (NMA). Until last few decades NMAs in most countries had a monopoly in producing topographic maps and related in-formation because of their techniques and productivity. Beginning in the mid-1970s these monopolies became increasingly challenged due to the growing proliferation of information technology (IT) (Groot R., 1999). Topographic map production system in NMAs has evolved over time. The nature of evolution can be explained as sets of changing factors –challenges – NMAs’ responses. The objective of this chapter is to identify key aspects that force dramatic change in the NMAs and their continuum challenges. In the first two sections of this chapter evolution of topographic map production system and work procedure of an example of current topographic map production system are described. In the next section key factors for change and business challenges of current system are researched. Among key factors In-formation technology is mostly elaborated in section 2.5.

2.2. Evolution of topographic mapping system

NMAs’ major goals are to provide topographic and related data, including national referencing system to public and private sectors. With changing environment the status of NMAs has changed tremen-dously. Studying history of NMA provides us some clues to the certain problems i.e. identification of key environments of NMA and business challenges. In this research three aspects of NMA are identi-fied to trace the evolutionary stage of NMA. These are including mission, products and services, and information technology. Table 2 – 1 shows overall view of evolutionary stage of the system.

2.2.1. Mission

Oxford (95) defines the mission as a particular task done by a person or a group, a particular aim or duty that one wants to fulfill more than anything else. Mission states the primary function of the or-ganization, defines and justifies why the organization exists (Paresi C., 2001). Groot R. (1999) pro-posed the stages in the evolution of the mission of a fictitious NMA as follows: Pre 1970 To produce and maintain topographic map at the scales…, according to the standards of the national topographic mapping system. Mid 1970’s To ensure the timely availability of up to date topographic maps at the scales …, according to the standards of the national topographic mapping system.


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Table 2-1 Evolution of Topographic Mapping System

•Aerial Photographs•Satellite Images•Total station, GPS•Digital photogrammetry

•Aerial Photographs•Electronic Distance Measuring Device (EDM)•Analogue/Analyticalphotogrammetry

•Field Measurement•Mechanical/Optical Distance Measuring Device (MOD)•Field survey

Data Acquisition

•Maintaining data within database management system(DBMS)

•Archiving in digital format

•Archiving in paper format

DataManagement

Information Technology

•Computer aided cartographic process•Diverse Map sales•Data access and delivery through the Internet

•DTM (Grid, TIN)•Orthoimagery•Topographic database (Topology-built format)•Topographic maps (derived from Topographic database)•Network data (e.g. road, hydrology, utility)

Mid to End 1990’s•To ensure the timely availability of up to date topographic information of national scope, according to nationally accepted data standards, and standards of integrity, formats, etc.

•Computer aided cartographic process•Limited Map sales•Digital data supply (CD-ROM)

•Aerial Photos •Geodetic control points (Text, ASCII format)•Topographic maps (scanned map)•Topographic data (File based Non-Topology CAD format)

Mid 1970’s•To ensure the timely availability of up to date topographic maps at the scales …, according to the standards of the national topographic mapping system.

•Manual cartographic process•Paper map supply

•Topographic maps•National TriangulationPre 1970

•To produce and maintain topographic map at the scales …, according to the standards of the national topographic mapping system.

Data Visualization &

Distribution

Products and ServicesMission

•Aerial Photographs•Satellite Images•Total station, GPS•Digital photogrammetry

•Aerial Photographs•Electronic Distance Measuring Device (EDM)•Analogue/Analyticalphotogrammetry

•Field Measurement•Mechanical/Optical Distance Measuring Device (MOD)•Field survey

Data Acquisition

•Maintaining data within database management system(DBMS)

•Archiving in digital format

•Archiving in paper format

DataManagement


•Computer aided cartographic process•Diverse Map sales•Data access and delivery through the Internet

•DTM (Grid, TIN)•Orthoimagery•Topographic database (Topology-built format)•Topographic maps (derived from Topographic database)•Network data (e.g. road, hydrology, utility)

Mid to End 1990’s•To ensure the timely availability of up to date topographic information of national scope, according to nationally accepted data standards, and standards of integrity, formats, etc.

•Computer aided cartographic process•Limited Map sales•Digital data supply (CD-ROM)

•Aerial Photos •Geodetic control points (Text, ASCII format)•Topographic maps (scanned map)•Topographic data (File based Non-Topology CAD format)

Mid 1970’s•To ensure the timely availability of up to date topographic maps at the scales …, according to the standards of the national topographic mapping system.

•Manual cartographic process•Paper map supply

•Topographic maps•National TriangulationPre 1970

•To produce and maintain topographic map at the scales …, according to the standards of the national topographic mapping system.

Data Visualization &

Distribution

Products and ServicesMission


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End 1980’s To ensure the timely availability of up to date topographic information of national scope, according to nationally accepted data standards, and standards of integrity, formats, etc. … Mid to End 1990’s To ensure the timely availability of up to date topographic information of national scope, according to nationally accepted data standards, and standards of integrity, formats, etc. … and to actively promote the use of this information in value added applications relevant to the market, on the basis of prices which will … (for example support the maintenance of the database.) The development of above mission statements show the several important characteristics of NMAs such as degree of customers’ involvement, available products and services, quality of products, etc. The last mission statement is the one that is considered as TO-BE situation and followed by process modeling in chapter four.

2.2.2. Products and Services

The number of products and services from NMA is increasing because of users’ require-ments, technology, legal mandates, etc. It is difficult to classify products and services into certain categories. However, the following are products that are generally available in the NMAs. In this paper products and services are not differentiated because both of them have the same meaning to the customers in the context of business (Jacobson I., 1994).

- Topographic maps (Hard copy) - National Triangulation (Monuments and coordinates) - Aerial Photos (Hard copy, Soft copy) - Geodetic control points (Text, ASCII format) - Topographic maps (Soft copy) - Topographic data (File based Non-Topology CAD format) - Digital Terrain Model (DTM) (Grid, Triangulated Irregular Network (TIN)) - Orthoimagery (Aerial photos, satellite imagery) - Topographic data (File based Topology-built format) - Topographic maps (vector and raster format derived from Topographic data) - Network data (Properly structured for network analysis e.g. road, hydrology, utility)

In addition to those products mentioned above some NMAs are providing more products and services to the customers. Those are listed below:

- Topographic DB (geodata stored in RDBMS) - LIDAR or SAR data - National GPS Network (GPS stations and coordinates) - National Geospatial Data Infrastructure (NGDI)

Although not all of above products and services are available from majority of NMAs at the moment, many of them are planning to change or on the way of changing in order to make them to be able to produce the new products and services.


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2.2.3. Technology development

Technology is one of the most important components for the NMAs. It drives the mapping organiza-tion into the new stage. According to the experiences about development of NMAs in all over the world, they have been changed significantly in both managerial and operational levels by applying new technologies. There are three main areas such as Data Acquisition, Data Management, Data Visualization and Distribution where technology development can be seen.

2.2.3.1. Data Acquisition

It is believed that data acquisition task is the most expensive and time-consuming task in the mapping organization. 1) Data Sources As the foundation geospatial data provider, NMAs are collecting the necessary data mostly from scratch. Information technology has enabled to make use of various data sources. The data sources that have been used in NMAs are introduced as follows: a) Field Survey

Before photogrammetry was accepted as a primary method for data acquisition, field surveyor had a responsibility for all necessary data capturing. All data were acquired by field surveyor with surveying instruments and drafted on the paper with drawing materials. b) Aerial Photographs Aerial photograph has been used since the early 20th century. Nowadays almost all topographic maps are based on aerial photographs. Aerial photograph can be divided into two categories: vertical photo-graph and oblique photograph. For mapping purposes vertical photograph is mostly used. Vertical aerial photograph taken in stereo enables stereo plotting and measuring height information. c) Satellite Images Since satellite remote sensing for earth observation started in 1970s, satellite images have been emerged as a primary sources for GIS application because of cost-effectiveness and continuous data provision. But up to now these satellite images are not widely used for topographic map production due to the insufficient spatial resolution. Current development in satellite remote sensing enables making use of satellite images for topographic map production. For example, IKONOS, owned by SpaceImagingTM, was launched in 1999 and has been delivering data since 2000. Spatial resolution of IKONOS data is 1m in panchromatic and it can be used for small and medium scale topographic map-ping. Table 2 – 2 shows the main characteristics of satellite currently being in operation.

Landsat - 7 SPOT - 4 IRS – 1D IKONOS

Swath width 185 km 60 km 70 km 11 km Off-track viewing NO YES YES YES

Revisit time 16 days 4-6 days 5 days 1-3 days

Spatial Resolution 15m (PAN)

30m (MULTI) 10m (PAN)

20m (MULTI) 6m

1m (PAN) 4m (MULTI)

Table 2-2 Earth Observation Satellite (From Principles of Remote Sensing)

2) Data acquisition techniques


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Various data acquisition techniques have been used in NMAs. The techniques showing development stage of NMAs very well are described here with explanation about important instruments. a) Field surveying The usefulness and applicability of topographic maps are dependent on the accuracy of the source data used in their preparation. One method used to collect source data is the field survey. Surveys are the result of systematic procedures used to measure the relative features and characteristics of the earth’s surface. Development of surveying equipment is explained as follows.

Mechanical/Optical Distance Measuring Device (MOD) These devices require visual sighting and determination of distances and angles by optical and/or physical measurements. Traversing is the procedure for determination of direction and lengths of the surveyed features and leveling is for the height. Transit, theodolites, level are the typical example of the MOD.

Electronic Distance Measuring Device (EDM) EDM has fewer restrictions than Mechanical/Optical Distance Measuring Devices. EDM does not require physical process of measuring linear distance, angles or elevations. It obtains those measure-ments by calculating transmitting signals from target reflector. Because of this EDM decreases the number of members and time needed on survey and increases accuracy of measurements.

Total station A total station is an advance field instrument of electronic distance measuring device (EDM). Besides the functions available with EDM the total station also includes a simple calculator to figure the ac-tual locations of points sighted (x, y, and z or northing, easting and elevation). The calculator can per-form the trigonometric functions needed, starting with the angles and distance, to calculate the loca-tion of any point sighted. Many total stations also include data recorders. The raw data (angles and distances) and/or the coor-dinates of points sighted are recorded, along with some additional information (usually codes to aid in relating the coordinates to the points surveyed). The data thus recorded can be directly downloaded to a computer at a later time. The use of a data recorder further reduces the potential for error and elimi-nates the need for a person to record the data in the field.

Global Positioning System (GPS) GPS is the only system today able to show the exact position of features above or on the earth. 24 GPS satellites are continuously monitored by ground stations located worldwide. The satellites trans-mit the signals that can be detected by anyone with a GPS receiver. Using GPS receiver, the surveyor can determine designated location with great precision. GPS technology provides increasing data ac-curacy and time saving.

b) Photogrammetry

Photogrammetry is the science and technique of making measurements from photos or image data. It is the primary technique for data extraction from data sources. Photogrammetry addresses the subjects of georeferencing, orientation, triangulation, feature extraction, and digital terrain modeling. With technology development more advanced instruments help better perform those tasks. Photogrammetric instruments can be divided like below.

Analogue Photogrammetry


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Introduction of analogue photogrammetry into mapping organization gave great improvement on pro-ductivity and quality control. Field survey is used only as a supplement and complement to get the ground control points and to identify unknown features from aerial photograph. The time needed to get the information about ground decreased dramatically. Operators drafting features can check his or her work in real time. Analytical Photogrammetry Computers have become common in almost every working area since last few decades. Photogram-mety together with computer technology gave great possibilities to mapping organization. Computer substitute labor-intensive operator’s works such as orientation, triangulation and other types of calcu-lation. Combination of photogrammetry and computer technology offers not only productivity im-provement but also opportunities of new products and services. Digital Photogrammetry Development of computer technology offers more possibilities to the data acquisition. Digital photo-grammetric workstation (DPW) is the one that includes new features of computer technology into the data acquisition task. It facilitates the use of diverse raw material like satellite image and radar image. Product diversity became possible due to DPW. DTM and orthoimagery are the good example of new products that are not available in previous production system. C) Remote sensing

Remote sensing means the study of objects from far away without actually touching them. Here the definition is limited in satellite remote sensing. Compared with aerial photography, satellite can provide data with reduced cost in short period. This advantage enables obtaining up to date data and latest change detection on the ground over time. Image processing is a vi-tal part of most remote sensing operation. It can be divided into two distinct stages: pre-processing, second stage image processing (Legg C., 1994).

Pre-processing Pre-processing is closely related to quality of satellite image. It includes earth rotation correc-tion, noise correction, radiometric correction, atmospheric correction and geometric correc-tion. Most NMAs are outsourcing for obtaining the satellite images. Therefore NMAs should have the specification about satellite image that specifies the quality of the data such as acqui-sition date, spatial and spectral resolution, covered area, etc. In most cases, geometric correc-tion is carried out in NMA.

Second stage image processing The second stage of image processing includes image enhancement and information extrac-tion. Image enhancement improves the appearance and interpretability of the image for visual interpretation. Contrast stretching, filtering, image fusion are the techniques used for image enhancement. Information extraction is the process that produces the required information from the satellite image. This processing can be done by interaction with operators or prede-fined classification method. Image enhancement and information extraction depends on the final products so that it should be clearly defined in the specification that which processing techniques must be used for the products. 3) Comparison on performance Performance of topographic map production system can be defined in terms of production cost, time, and quality of products. It has been proved that all type of performances have been


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improved by implementing latest development of information technology. Labor-intensive operations such as field surveying, aerial triangulation entails expensive cost and long period. Those operations have been replaced by sophisticated instruments or computers so that opera-tors can be released from those routine operations and concentrate on quality of their work results. Real time quality check that is possible in digital environment contributes to reduction of work repetition that needs extra time and cost.

2.2.3.2. Data Management

NMAs produce and maintain a large amount of spatial and attribute data. Maintenance of acquired data is so important that more attention has being paid on data management. Development of informa-tion technology made it possible to store and maintain all necessary data. This fact has significant im-pacts on NMAs such as productivity increase, delivery of diverse products and services, increasing accessibility through various paths. 1) Archiving in paper format Until computer became available maps had been archived only in paper format. Once the process of mapping is completed the available product is only the final map in paper format. After completing whole process it is impossible to correct errors without going back to the first step. 2) Archiving in digital format Computer gave the ability of storing intermediary data as well as the final products in digital storage system. This ability makes it possible to reuse stored data for other tasks and provide new products to users requiring those data. Compared with completed topographic paper map, digital data have flexi-bility for manipulating different information separately. Various products can be derived from digital data by combining each other. Although data are stored in digital format it is still difficult to use those data directly. The data stored in storage system, often called file based storage system, are no more than collection of proprietary file format of the system being used in NMAs. In most cases users are responsible for data conversion in terms of data format and thematic meaning in order to use them in their own software and application domain. 3) Maintaining data within database management system (DBMS) Data is handled with great care for maintenance and access from internal and external users. Database management system is used to manage a large amount of data. Data are stored in central or distributed data servers, and internal or external users can access to the data servers through the appropriate inter-face. Meta data is linked to data so that data users can find the data easily and correctly. Users can access to data servers through the internal network or Internet. In this DBMS environment data manipulation such as data updating and querying is easier and more consistent than file based storage system.

2.2.3.3. Data Visualization and Distribution

Data visualization and distribution are the final tasks of NMAs that actually produce and deliver the products and services to the customers. Development of these tasks heavily depends on previous tasks in topographic map production system such as data acquisition and data management. 1) Cartographic and Reproduction process Cartographic and reproduction process are mainly related to the production of hard copy maps. Map generalization is the main task in cartographic process. This task was often done by human operators so that it needed skilled operators and often produced inconsistent results due to different operators’


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decision. Introduction of database and GIS makes it possible to automate some part of generalization task. Embedding predefined symbolization algorithm and utilizing feature information stored in data-base replace a great part of human operation. These techniques contribute to reduction of cost in time and labor and producing consistent products according to map specifications. Map generalization techniques are still being researched. At this moment most NMAs use these techniques to complement human operation. 2) Map Sales Besides mandated distribution, NMAs are advertising and marketing their products and services to the potential users. In addition to topographic templates NMAs are selling various kinds of value added products. For example Ordnance Survey (OS) in UK has reached almost 100% cost recovery from selling products and services (Groot R. & McLaughlin J., 2000). The number of kind of products sold by NMAs is increasing from standard topographic map to user defined thematic data. There are insti-tutional and economical problems that must be addressed about map sales by NMAs. It is that how to guarantee a fair competition between NMAs and private competitors. Groot R. (2000) suggested three strategic goals of government to facilitate and effective competition. 3) Digital data Supply Since computer took the main role in production system NMAs have been supplying digital geospatial data. Although digitalization facilitates data supply, distribution of data has many limitations such as types of data, level of detail, area, etc. National Geospatial Data Infrastructure (NGDI) has the signifi-cant role in data supply. The NGDI deals with the geospatial data at the national level (Groot R. & Kraak M., 1999). Most NMAs at this moment supply digital data by CD-ROM. The specification of data is still defined by providers and users have limited extent of data selection in terms of area, the-matic layer, etc. Users do not want the whole data within one tile or layer rather they want to obtain the data exactly what they need. Those problems are the new challenges to NMAs. Internet is consid-ered as a main delivery path of digital data. In the near future the users can decide themselves the area of data and necessary layers.

2.3. Work procedure of an example of current production system

Topographic Map Production system using analytical and digital aerial photogrammetry techniques is the main production line in many National Mapping Agencies. Although they are using digital photo-grammetric techniques the production process is still the same as they are using analog techniques. For the sake of simplicity it is assumed that current topographic map production system is installed only analytical photogrammetric equipments. The overview of production system is given in Figure 2 – 1. a) Project Planning The objective of this task is to design, plan and monitor the production line in order to produce the required products. Activities in this task are: • Define products and product specifications • Analysis of resources and production constraints • Check production lines, tasks involved in each line and procedure for quality assurance. • Assign tasks and define production rates • Monitoring the production and data flow on the task level as well as on the project level • Design procedure to manage any changes on the production line


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Input • Product specifications and quality standards • Status of resources in each production line Output • Project schedule and plan b) Acquire Aerial Photography The objective of this task is to plan and execute the flight mission and makes them ready to use for next tasks.

Figure 2-1 Work procedure of a current topographic production system Activities • Set specification for flight and aerial photography as specified in the national standards for map-

ping • Design flight configuration (flying height, camera parameters, flight coverage, Number of photos,

number of strips, forward and side overlap percentage, etc.) • Conduct flight mission • Develop the film, produce photographs and check flight lay out • Photographic production (photo prints, diapositives) and photographic quality check • Archive photography for project use and orthophoto production • Report to the project manager Input • Project schedule and plan • Weather forecast information • Flight coverage specification

Project Planning

Acquire Aerial Photograph

Field Surveying

Aerial Triangulation

Feature Extraction

Field Completion

Produce Map-sheet data

Cartographic and Reproduc-tion Process

Create TopoDB


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• Photograph and diapositive specification Output • Flight plan and configuration • Photos and diapositives • Report about work Quality control • Flight coverage • Quality of Photograph and diapositive c) Preparation for Field Survey The objective of this task is to prepare all materials for field survey and identify ground control points (GCPs) needed for aerial triangulation. Activities • Design control configuration and locate the GCPs and the triangulated points in the photographic

block, as specified in the national standards for mapping • Transfer the selected points in the overlapping photos and prepare observation index of each

points for the aerial triangulation • Check transferred points and observation index • Archive observation index Input • Aerial photographs and block • Aerial triangulation procedure specification Output • GCP configuration • Annotated enlarged aerial photographs • Observation index data Quality check • Validation of GCP configuration • Point transfer in the photographs d) Field Surveying The objectives of this task is to determine the geodetic coordinates of selected GCPs Activities • Specify the accuracy requirements for field measurements as specified in the national standards.

(horizontal accuracy, vertical accuracy) • Verify the GCP configuration in the field and complete the GCP description forms • Field measurement and computation of coordinates (X, Y and Z coordinates) • Check the quality of measurements • Archive of control points in database • Report about field surveying Input • GCP configuration • Annotated enlarged aerial photographs Output • Archived data of GCP Coordinates


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• Report about field surveying Quality control • Horizontal and vertical accuracy e) Aerial Triangulation The objective of this task is to determine the geodetic coordinates of all control points needed for ste-reo restitution. Activities • Prepare observation schema, camera parameters, observation index, and instruction for measure-

ment and coordinates for the ground control points • Establish and refine photo coordinates by interior orientation • Points measurement • Strip and Bundle adjustment • Check the horizontal and vertical accuracy • Archive the coordinates of the ground control points Input • Aerial photographs and camera parameters • Observation data GCP measurements Output • Supplemental ground control points data Quality control • Horizontal and vertical RMSE (Root Mean Square Error) f) Photogrammetric Feature Extraction The objective of this task is to extract terrain features including identification of the required features, assign class, trace of feature boundaries and its topological relations with neighboring features. Activities • Define feature classification and coding method • Stereo restitution (interior orientation, relative orientation, absolute orientation with the result of

aerial triangulation) • Match this model with neighboring models and insure consistency in the overlapping areas • Interpretation and feature tracing (3D digitizing) • Check quality of digitizing (completeness, over/under shoot, close areas, class code, etc.) • Form topology with arcs and nodes • Check edge matching with overlapping models and take corrective actions • Archive digitized data (model based data) • Produce check plot for field completion Input • Aerial photographs and camera parameters • Supplemental ground control points data • Feature classification instruction Output • Digital photogrammetric data • Printed check plot Quality control


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• Digitizing quality, completeness, consistency, classification, etc. • Topology checking (redundant nodes or missing nodes) g) Field Completion This task is for field verification and collection of feature names. Activities • Check completeness, digitizing quality, feature formation and classification • Collect the names of the features of interest • Archive field data and collected names • Check plot with test points (x, y, z coordinates) • Geographic name data • Map accuracy standard • Field completion data (field check result and geographic names) Quality control • Horizontal and/or vertical accuracy of test points • Validation of digitizing and classification h) Produce Digital map sheet data The objective of this task is to carry out final verification of the photogrammetric data and formatting the photogrammetric data into the map sheet based data. Activities • Define schema for map sheet formation and group the data files on the bases of the individual

map sheet that they cover • Form the map sheet data file by clipping the data files on the map sheet boundary • Check topology and edge matching and take corrective action • Archive map sheet data into specified digital format such as DXF, SDTS, etc. Input • Digital photogrammetric data • Field completion data Output • Digital map sheet data in specified data format Quality control • Feature classification, topology, edge matching, data extent (map sheet) i) Cartographic processing The objective of this task is to restructure and modify the digital map sheet data in order to produce topographic map as specified in the national standards Activities • Define color separation schema and reclassify feature class • Produce frame, grid and marginal information specified in national standards • Resolve graphic conflicts (aggregate, remove, displace features, etc.) • Symbolization and text placement • Check and correct cartographic actions • Archive soft copy color separates in cartographic database Input • Digital map sheet data


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Output • Cartographic data (soft copy of color separate) Quality control • National map specification including map accuracy • Map symbol, text placement, map frame, marginal information, Grid j) Reproduction processing The objective of this task is to produce color separate plate in order for mass production of topog-raphic map Input • Cartographic data (soft copy of color separate) Output • Color separate printing plates • Printed maps Quality control • National map specification including map accuracy • Map symbol, text placement, map frame, marginal information, Grid k) Create Topographic Database The objective of this task is to create national topographic database from digital map sheet data. Activities • Check database schema (database structure, data quality, representation of spatial relationship,

identification of boundary-crossing features, metadata structure etc.) • Restructure and reclassify features into the database schema • Collect additional data for the extra attributes in topographic database • Take necessary actions for spatial relationships within or different categories and boundary cross-

ing features representation • Check data integrity within topographic database • Archive topographic database into specified data format Input • Digital map sheet data • Topographic database schema Output • National topographic database Quality control • Data integrity, spatial relationships, boundary crossing features

2.4. Business Challenges for change

Environment of a business is changing over time. In this section the important factors forcing changes in the NMAs and the challenges that NMAs are facing with are identified.

2.4.1. Key Drivers to change

National mapping agency is strongly being pressed to change in order to make it competitive and ef-fective. Monopoly given to NMA is no longer exist or limited in as small extent as possible and strong competition comes. Therefore, NMA has to adopt new strategy to come up with new environment. When defining strategy, sound analysis of external environment is prerequisite in first priority. The


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question that who has what role to organization should be answered before defines how to achieve organization’s goal. The introduction of Information and Communication Technology (ICT) and the political factors such as governmental innovation and reformation, new legislation, etc. have forced NMAs to critically review their mandates and determine how the biggest return on the investment in national surveying and mapping by society can be realized (Groot D. & Kraak M., 1999). Paresi C. (2001) identified changing environment of NMAs including changing government’s policies, chang-ing customer’s requirements, changing market situation, and enabling technology. Below is the over-all picture of the context that contains NMAs and key factors encouraging them to change.

Figure 2-2 Key drivers to change

2.4.1.1. Budget constraint Due to the serious governmental deficits, most countries have been trying to reduce the size of gov-ernment and funds. Many governmental organizations have been privatized or independent from gov-ernmental intervention. National mapping agency is also confronted with the pressure of being inde-pendent organization. It means that some portion of cost should be recovered by its own income. This situation requires new business paradigm. There are significant successes in some organizations in-cluding the Netherlands’ Cadastre, Service New Brunswick (SNB), the Ordnance Survey of Great Britain (OS), the Danish National Survey, and the NMA of New Zealand (Groot R., 2000). For exam-ple OS has sought full cost recovery policy. Significant changes on organizational structure and proc-

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1988 1989 1990 1991 1992 1993 1994 1995 1996 1997

Date

Perc

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National Mapping Agency

Budget Constraint


New Legislation GIS Market

Customers’ Requirement


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esses have taken place to make the organization able to be self-sufficient. From past few years, almost 100 % of cost has been recovered from sales of information and services (Groot R. & McLaughlin J., 2000).

Figure 2-3 Level of cost recovery of OS (from Groot R. & McLaughlin J., 2000)

2.4.1.2. New Legislation

Mandate imposed on NMA is to provide standard paper maps to governmental and private customers. Geo-information is linked to numerous different fields such as environment protection, natural re-source management, national defense, transportation and construction, etc. For example National Geologic Mapping Act in 1992 established a National Cooperative Geologic Mapping Program in the U.S. Geological Survey (USGS). To response to the this Act USGS (1) determined the Nation's geo-logic framework (2) developed a complementary national geophysical-map database, geochemical map database, etc. that provide value-added descriptive and interpretive information to the geologic- map data base; (3) applied cost-effective mapping techniques (4) developed public awareness for the role and application of geologic-map information (referred to USGS web site). Due to the new Act some or whole part of organization should be redesigned to perform new mandate.

2.4.1.3. Customers’ Requirements

Customers’ requirements are the most important consideration for the business organization like NMAs. Groot R. (2000) divided customers of NMAs into two parts i.e. end-users and value-adding users. End-users take the foundation data and add attribute values or other thematic data for their own pur-pose. Value-adding users do the same for re-sale to third parties. Those requirements from the customers are subject to change along with the social, economical, tech-nological situation. To be responsive to the change of customers’ requirements NMAs must pay strong attention to monitoring and responding to them. Paresi C. (2001) stated diverse and up-to-date products, fit for purpose, timely delivery as the main customers’ requirements.

2.4.1.4. GIS Market

Because of government’s reform to privatization, NMAs became one of competitors in the GIS mar-ket. GIS market strongly influences mission, vision and strategy of the NMAs. The size of GIS market is growing fast since new technology enables product diversity and cost reduction. In GIS market, main commodity has been shifted from paper map to various kinds of digital information. Further-more the surveying and mapping which were the specialties of NMAs in the past became challenged due to the growing proliferation of IT (Groot R., 2000). New competitors are coming out and competi-tion becomes strong. From the customers’ point of view they have the freedom of choice of products and services according to their purposes. To remain competitive power in GIS market NMAs must monitor the change of market and adapt to the change.

2.4.1.5. Information technology

Information technology is the main driver for NMA to change into new direction. It gives a lot of po-tentials to NMA that are not possible before. For example automatic feature extraction, producing orthoimagery, using GPS on determination of coordinates, automatic DTM generation, etc. is possible by using new technology. It allows NMA to deliver diverse products and secure the quality of all


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products. Introducing new technology into legacy system requires change on all part of organization such as organizational structure, process, resource allocation, and how the organization is managed.

2.4.2. Business Challenges

As one of business organization, NMA is confronted with several challenges. Those challenges are inevitable for NMA to gain competitive power in GIS market and should be taken into consideration during defining the vision of the new business.

2.4.2.1. Customer focused

Organizations depend on their customers and therefore should understand current and future customer needs, should meet customer requirements and strive to exceed customer expectations. (ISO, 9000:2000) Customer requirements should be considered and implemented in whole organizational activities. Customer satisfaction is the first priority of performance measurement because it is a prerequisite to the success of the organization. Customer requirements analysis The result of customer requirements analysis is an essential input to develop business mission, vision and strategy. Customer requirements point out that what kind of products or services should be deliv-ered. In order to collect customer requirements and expectations, the organization should deploy con-tacting mechanism with customers. Customer satisfaction measurement Customer satisfaction measurement is an iterative process which in turn introduces new customer re-quirements into the organization. It includes surveying customers’ satisfaction as well as competitors’ performance in market. The measuring satisfaction is completely subjective and experiential so that regular contact with customers should be designed to get necessary information.

2.4.2.2. Be ready to changing environment

Organization environment is subject to change with time. Nowadays environment changes so fre-quently that it is very difficult to respond to the impact of that change. Those organizations that do not respond in time will lose their competitive power according to market principles. Of particular concern is the readiness of the NMA to change the organization and methods of working in line with the requirements of this mandate and especially the growing need of the user community for a diversity of products rather than standard ones (Rhind D., 1997). Research and development team (R & D) in organization is dedicated to monitor the change of envi-ronment. Possible alternatives are studied and selected in order to get strong competitive power in new environment. Appropriate investment should be secured on R & D activity. A Clear understand-ing of business organization facilitates improvements to the business and helps identify new business opportunities. Well-documented business will help all stakeholders of that organization make them-selves ready for change.

2.4.2.3. Effective use of IT

Information technology has a huge impact on almost all activities in mapping organization. Introduc-tion of new IT to mapping organization involves all levels of staff. The benefits from IT include cost


24

savings, speed and flexibility in data collection, storage, retrieval, communication and presentation. The number of products and services increases by using new technology. Advanced technology leads the organization to high productivity. Marketplace is also changing because of new information order-ing and delivering method i.e. the change on customers’ access to mapping organization and vice versa. Effective use of IT is the major challenge for a mapping organization. The cost needed for im-plementation of new IT is quite expensive. Maintenance cost is usually more than initial investment. In most developing countries, it restricts introduction of new IT into mapping organization. Another challenge is training staffs who believe that they have competence on old system. Management has the responsibility to persuade them to take potentials of new IT and to educate them. Greenway I. (2002) proposed the principles of strategic management of IT in organization. He introduced four main principles of management of IT in organization: Investment principles, Infrastructure principles, Data principles and Organization principles.

2.4.2.4. Provision of various products and services

Traditionally, national mapping agency is committed to deliver topographic map series through the mass production system. At present, the users need to have information either in analogue or digital format. The GIS users are more interested in geo-information in digital form for further purpose. To meet users’ requirement, the focus should be shifted from mass production of one product to delivery of diverse products and services. National mapping agency deals with huge amount of spatial data costing majority of total production cost. However, it is very difficult to reuse those data for produc-tion of other products in traditional production system. To achieve product diversity, those spatial data should be stored and processed with caution according to specification. One product can be de-livered to customers as well as an input for next products. If the output of one process is not consid-ered with respect to next product, the process for next product has to start from scratch. Production of the similar products is the same. Figure 2 - 4 shows hierarchical configuration of product diversity and process complexity.

Figure 2-4 Diversity of Products (Prado D., 1998) Integrated production system needs to be established to make sure optimized control over the whole process. Defining specification for each products and services is the new challenge emerging with product and service diversity. Modeling integrated process in conjunction with appropriate specifica-tion is examined in following chapters.

Electronic atlas,OrthophotomapsInformation in the Net

Topographic data &Thematic Information

ImagesPhotographsField data

Stock of skilled productsproduced in Request

Stock of ConventionalProducts to be sold

Raw Material

Prod

uct C

ompl

exity

Proc

esse

s C

ompl

extiy


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2.5. Advantages of New Information Technology (IT)

Information technology (IT) is the main supporter enabling mapping organization to keep pace with changing environment. Information technology is basically related to most of the disciplines in map-ping organization i.e.: data acquisition, data processing, data retrieval, and distribution of data. Intro-duction of new information technology into the mapping organization causes significant operational change. Hereafter information technologies being closely related to topographic map production sys-tem and their advantages are researched.

2.5.1. Geodesy

Geodesy is the discipline that surveys planimetric and altimetric location of the object on the ground. Trigonometrical survey, plane survey has been applied to this discipline for a long time. Those meth-ods provide more or less reliable result but strongly affected by surveyor’s ability. It takes a lot of time because of manual calculation and frequent movement and setting up. The accuracy is the most important performance indicator. Also, this is one of the most time consuming tasks in mapping or-ganization. Reducing time and increasing accuracy is the first problem to be solved in this discipline. GPS is considered promising solution for both problems. GPS stands for Global Positioning System. It is believed that GPS shows exact location on the Earth at any time, in any weather at any place. Many mapping organizations in developed countries already deployed GPS receivers for field survey-ors. GPS-equipped aircraft for aerial photo can obtain exact coordinates of center point of each photo. These coordinates are used for adjustment of digital aerial triangulation. It has been proved that appli-cation of GPS in mapping organization guarantees accuracy and time and cost effectiveness.

2.5.2. Photogrammetry

Photogrammetry is the core discipline in mapping organization. Digital photogrammetry has intro-duced production of orthoimage, digital aerial triangulation, automatic DTM generation and mapping. The majority of mapping organization are using analytical plotter, even some are still using analogue plotters. Digital photogrammetry workstations are replacing them because of high productivity and flexibility in operation. The potentials and limitations of digital photogrammetric workstation having been examined since it came to market. Advantages of digital photogrammetric workstation in main photogrammetry operations are explained below. Digital Aerial Triangulation Aerial Triangulation is the process for densification of ground coordinates. It is the most time-consuming process in photogrammetry discipline in analogue or analytical environment. Originally, digital photogrammetry workstation was limited to relative and absolute orientation. Later, aerial tri-angulation functionality was added. Basic procedures of aerial triangulation are: photoblock prepara-tion, inner orientation, measuring tie points, measuring GCPs, block adjustment, and correction. Digi-tal photogrammetry workstation carries out some of above steps automatically. Digital aerial triangu-lation contributes to increasing productivity and saving time. Some products are available commer-cially and applied to mapping organization in some countries. Automatic DTM generation Digital Terrain Model (DTM) is the numerical model that records the shape of the earth’s surface by means of elevations above a given datum. (Weibel R., 1997) Until now the procedure of DTM genera-tion is mainly performed by operator’s manual interpretations using analytical plotter. After drawing contour lines, the model is converted to required format such as grid or TIN. This procedure requires


26

skilled operators and huge amount of time. With the digital photogrammetric workstation, automatic DTM generation became possible. It serves clear accuracy and economy advantages over conven-tional analytical DTM generation. Operator’s interactive editing with automatic DTM generation is necessary for quality control and high accuracy. Although the main direct application of DTM is the orthoimage production, DTM is considered as a foundation data for GIS. Orthoimage The demands of orthoimage from customers are increasing in GIS domain. Orthoimage has many benefits including wealth of information, similarity to reality, good readability, exact geometric and up-to-datedness. Orthoimage can be used as backdrop for a GIS and can be used for 2-D digitizing. Digital photogrammery workstation allows producing orthoimage within standard production system in mapping organization with slight modification. Rectification is a process of removing the effects of tilt, relief, and many of the lens deviation from the standard perspective photographs. Orthoimage is delivered in digital or analogue format to customers according to their needs. Feature Extraction (StereoPlotting) Stereoplotting is the core task that extracts terrain features and identifies topologies between features. Stereo-restitution is the first step for feature extraction. This task is almost done automatically by im-porting stored orientation parameters. Digital working environment offers freedom of image manipu-lation to the operators. For example, roaming, zooming in and zooming out of image are being done without difficulties. Superimposition of the existing vector data on image makes it possible that opera-tors can check the quality in real time. From the operator’s point of view, this working environment offers more comfortable to the operators.

2.5.3. Cartography

Cartographic task is the most time-consuming task in mapping organization because of manual opera-tion. It includes classification, aggregation, symbolization and displacement of features according to map specification. New technology significantly reduces the time spent for most activities mentioned above. Operators can define feature representation specification in advance so that symbolization and classification can be done with minimum operator’s interference. Soft copy of color separation is stored in server so that the organization can respond to the emergent call for paper or digital map. New technology allows product diversity by using various representation capabilities. 3 –D topog-raphic map, orthomap, various kinds of thematic maps are good examples.

2.5.4. Database Management System (DBMS) within GIS context

Databases are traditionally used in business and administrative applications. Relational database man-agement system (RDBMS) has been proved an ideal database system for the enterprise information system. It provides consistent updating and retrieval of data, security of data access, concurrent trans-action, etc. However, handling spatial data requires new technologies in database application i.e. stor-ing geometry, large size data handling, identification of spatial relationships and spatial query. As us-ers’ needs for location-based information increase, many manufacturers are trying to develop spatial database in RDBMS. Some of them are already commercialized. By linking spatial and non-spatial data, users can query spatial objects by attribute information. But most of commercialized products applied hybrid structure that spatial and non-spatial data are stored in separate data respectively con-nected by object-ID.


27

With this separated data structure, it is difficult to manage the spatial data consistently. To overcome the problems on management of spatial data, some of advanced software manufacturers introduced object-relational database management system (ORDBMS) into GIS industry. ORDBMS takes rela-tional database model and extends it with certain object-oriented concepts. (Muller R. J., 1999) In GIS context, spatial aspects of features are represented by object concept. For instance, geometry of each feature is stored in one field in the feature table then this field is linked to geometry object. Since ORDBMS has become the new standard in database application, the need for enterprise wide spatial database became possible. ORDBMS manages spatial and non-spatial data in a single data-base. This system provides many benefits to manage spatial data in enterprise wise database e.g. • Full access to data and spatial functionality through the standard interface e.g. SQL • Using spatial data in non-GIS application such as word processor, spreadsheet, etc. • Facilitating data distribution through the network i.e. Internet, Intranet, etc. The trend in GIS industry is shifting from file-based architecture to database to better manage spatial data.

2.5.5. Network technology

Client – Server technology is the foundation technology that enables data sharing within or between organizations. Mapping organization is dealing with large amount of data that is supposed to be used by many internal operators as well as external users. Initially client – server architecture referred to 2-tiered file sharing architecture. This group computing has limitations when working in large enterprise in terms of performance and data security. New concept of client-server architecture to overcome obstacles mentioned above is the 3-tiered ar-chitecture. Between server and client, middle tier is included that manages transactions between them. The role of middle tier are queuing, prioritizing the requests. The requests from clients go to middle tier and processed according to defined business logic. In mapping organization data is the most important element that should be managed in consistent way. The change on data has to be monitored and checked before the work finish. The advance of technology in client-server architecture offers more possibilities such as application service. The clients do not have to install all softwares needed to perform their job. They can get the necessary application from middle tier as they get the necessary data. This technology enables data distribution through the Internet. Internet is the main path through which infinite number of information flow all over the world. Inter-net GIS refers that Internet is used as a means to access and transmit remote data and present GIS re-sults. Some of mapping organizations and private companies are providing geo-information through the Internet. There are still limits to display spatial data, execute full GIS function on the web browser due to the lack of spatial data definition protocol. XML is considered solution for those problems. XML stands for extensible Markup Language. It extends the capability of HTML by defining the definition and representation method for the new tags. Geographical Markup Language (GML) devel-oped by Open GIS Consortium is the specific type of XML that enables spatial data definition and representation of the Internet.

2.6. Concluding Remarks

The status of national mapping agencies is changing rapidly due to several causes. As we can see from its evolution stages, the national mapping agency is shifting from monopolistic to market driven or-


28

ganization against numerous competitors, from mass production of limited products to diverse prod-ucts and services provider. It is of utmost importance to understand key drivers forcing mapping or-ganization to take dramatic changes and its facing challenges in order to produce the vision of the fu-ture business. As the environments of the business are changing the vision of the business also must be changed to maintain or increase the competitive power. Information Technology has a great role in redesigning process of the business. It enables to take new opportunities into the business and increase productivity of the business. Adopting IT into the busi-ness must entails process redesigning in order to take full advantage of IT.


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3. GIS interoperability and Object-oriented business process modeling

3.1. Introduction

Redesigning the new business process needs comprehensive understanding of business process in-cluding goals, business constraints, activities, the available information technology, etc. In addition to comprehensive understanding of the business process, systematic methodology must be used to design the business process. Business process redesign or reengineering (BPR) is the basis on which dra-matic change is introduced and implemented into the business. In this thesis Open GIS Specification is considered as a main input of BPR effort for topographic map production system. Therefore, intro-duction of Open GIS Specification into the system must be modeled in systematic manner. This chapter firstly reviews the concept of interoperability in GIS industry and Open GIS Specifica-tion as a promising solution for GIS interoperability. Afterwards object-oriented process modeling technique is explained with the basic concept of Business Process Reengineering (BPR).

3.2. GIS Interoperability

The availability of advanced Information Technology and digital data sets is creating a big impact on the utilization of geodata in both public and private sectors. Unfortunately the main handicap for the expansion of geodata usage is that all these spatial data sets are captured and stored in a wide range of vendor proprietary formats, often incompatible with each other. The main problem is, therefore, the non-interoperability of GIS products which usually result in isolated repositories of geodata and geo-processing.

3.2.1. Definition of interoperability in GIS industry

Interoperability is the ability of a system or components of a system to provide information sharing and inter-application cooperative process control (Groot R. & McLaughlin J., 2000). As shown in Figure 3-1, two systems X and Y can interoperate if X can send a request for service R to Y on the mu-tual understanding of R by X and Y, and Y can return response S to X based on the mutual understand-ing of S.

Figure 3-1 Interoperability between different GIS (Groot R. & McLaughlin J., 2000)

Mutual understanding of R &

Request (R)

Response (S) GIS X GIS Y


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Open GIS Consortium (OGC) defines that interoperability is software components operating recipro-cally (working with each other) to overcome tedious batch conversion tasks, import/export obstacles, and distributed resource access barriers imposed by heterogeneous processing environments and het-erogeneous data (OGC, 1998). The basic principle is that all spatial data, which should be made avail-able over a network to large numbers of user groups by a number of data sources, conforms to a ge-neric model, even though the data might have been captured by different users using different GIS products and production systems. Interoperability is defined as ‘a user’s or ‘device’s ability to access a variety of heterogeneous resources by means of a single unchanging operational interface (Aybet J., 1997). For GIS users, it means the freedom and ability to access local or remote geoprocessing environments which may use multiple GIS products and contain multiple format data sets. The first logical step to achieve the full integration of geodata from a variety of sources and within a variety of applications would naturally be to establish a standard for the exchange of spatial data and its meta data.

3.2.2. Geospatial data exchange and access

Collecting or gathering spatial data is the most expensive activities in GIS domain so that GIS devel-opers and users have focused on sharing data for many years. In GIS industry, three distinct strategies for data sharing have been implemented as shown in Figure 3 – 2.

Figure 3-2 Geospatial data exchange and interoperability (From R. Groot & J. McLaughlin, 2000)

Direct Batch Translation Development of specific programs to translate formats directly from one proprietary structure to an-other. In any kinds of industry there are de facto standards that occupy major part of market. To gain competitive power in GIS market, one product would includes functionality converting from de facto standard to its own data format and vice versa. For instance, users of ARC/INFO from ESRI can im-port and convert data from MGE from INTERGRAPH.

Intermediate Batch Translation

Direct Batch Translation

Intermediate Batch Translation

Transparent Interoperability


31

Translation of specific vendor format to an accepted intermediate exchange format followed by trans-lation to another vendor’s structure. This approach gives more flexibility especially when multiple applications are involved in the data exchange. There are several industry standard exchange format which have been formally accepted by standard organizations, including • SDTS (Spatial Data Transfer Standard) developed by the FGDC (Federal Geographic Data Com-

mittee) in USA. • DIGEST (Digital Geographic Exchange Standard) developed by the DGIWG (Digital Geographic

Information Working Group) sponsored by NATO. • VPF (Vector Product Format) developed by NIMA (National Imagery and Mapping Agency) in

USA.

Transparent Interoperability This approach does not involve any type of translation that causes information-loss and time-consumption. Different systems can read, query, and analyze the data directly from another system. System means in this case different GIS software and the applications from different domains such as word processor, spreadsheet, statistics applications, etc. Ideally, this approach is the most appropriate way of data sharing. However, to achieve this, there must be a quite strong attention on technical, in-stitutional, economical issues. Interoperability can be achieved when all participants in standard de-velopment process agree on using certain standard. Standard development process carried out by Open GIS Consortium (OGC) is the good example of this effort. They already published several stan-dard specifications into the market so that majority of GIS vendors are following those specifications to increase market share.

3.2.3. Increasing demand for Enterprise GIS

Enterprise GIS indicates that GIS database becomes integrated components of an enterprise business process and data can be easily disseminated throughout the enterprise and can be easily maintained (Thomas G., 2000). GIS can, and should, be considered as a database problem with the additional re-quirements being geodetic coordinates systems, geometry, and graphics display (OpenGIS Simple fea-ture specification for OLE/COM, 1999). Integrating of GIS spatial data with the enterprise wide DBMS environment provides a powerful data warehouse solution for large data stores and solutions supporting a high number of GIS clients (ESRI, 2001). According to the definition of enterprise GIS some requirements can be extracted. Enterprise GIS should be able: • To integrate spatial information with enterprise wide attribute information • To support large number of users using various kinds of application • To secure data access, retrieval and manipulation • To make the spatial data available through the network environment, e.g. Internet, intranet, or

mobile computing

Data sharing and data connectivity to other enterprise database is the key to establishment of Enter-prise GIS. Many efforts have been endeavored to achieve those requirements. With the current available technology it is known that the best solution until now is the combination of GIS and relational database management system (RDBMS) or object relational database management system (ORDBMS). DBMS can provide the ability of data management such as data access, retrieval, ma-nipulation control and network distribution and GIS takes responsibility of GIS functionality such as spatial analysis, display and different types of location-based functionality. Some commercial prod-


32

ucts have been developed and being used in many enterprises such as ArcSDETM from ESRITM, Ge-omediaTM from Intergraph, Oracle SpatialTM from Oracle Corp., etc.

3.3. The Open GIS Specification (OGIS)

The Open GIS Consortium, Inc. (OGC) is a non-profit trade association dedicated to promoting new technical and commercial approaches to interoperable geoprocessing. (The OpenGIS Guide, 1998) The OGC consensus process involves all the participants in creating a software specification, the OpenGIS Specification, which is a comprehensive specification of a software framework for distrib-uted access to geodata and geoprocessing resources. Open GIS Specification will provide the solution to meet those requirements. Figure 3 – 3 shows the role of OpenGIS Specification in heterogeneous environment.

Figure 3-3 The role of Open GIS Specification (adopted from OGC, 1998)

3.3.1. Open GIS Specification (OGIS)

Open GIS Specification has been widely accepted through the overall GIS communities including software vendors, governmental agencies, other standard organizations and academies. The Open GIS Consortium (OGC) seeks to obtain interoperability through common specification. It means that soft-ware developers achieve interoperability by writing their software to conform to a common specifica-tion. The Open GIS Specification provides an object-oriented framework for access to geodata, inde-pendent of the specific data structures and file format used to model the data. With Open GIS Specification software developers can develop middleware, applications that can handle full range of geodata and geoprocessing functions. The Open GIS Specification includes three parts: Open Geodata Model, Open GIS Services, and In-formation Communities Model.

Open Geodata Model

The Open GIS Specification heavily depends on the definition of a common data model for the trans-fer of geographic information and the definition of the behavior of operations on that data. The Open Geodata Model provides a single comprehensive model for geographic information by means of ob-ject-oriented modeling. Therefore it is a core of Open GIS Specification. It is more elaborated in fol-lowing section.

File For- File For-File For-

File For-Real-Time Data Feed

File For-Traditional

DBMS

File For-File For-Non-traditional

DBMS

File For-

NETWORKS AND CLIENT/SERVER TECHNOLOGY

File Format

File Format

File For-

File For-

Interfaces based on the OpenGIS Specification


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Open GIS Services

The Open GIS Service Specification defines a common model for implementing services for access, management, manipulation, and sharing of geodata within and between Information Communities. The Open GIS Service Model will provide (Open GIS Service Architecture, 2001): • The means by which Open Geodata Model types can be collected to form complex models, que-

ried for selections of subparts, and cataloged for sharing within and between Information Com-munities.

• The means by which Open Geodata Model data types and user-defined data types can be defined and their operations executed.

OGIS Information Community Model

Information community is a group of geodata producers and users who share a set of geographic fea-ture definitions. By definition, their semantic schema, including metadata, spatial reference system, and geomatics functions, is the same. The OGIS Information Community Model specifies (The Open GIS Guide, 1998);

• A standard way to represent an Information Community’s semantics for the benefit of both members and non-members of the Information Community.

• A standard way to construct ‘semantic translators’ rather like bilingual dictionaries imple-mented in software, which provide a mapping between two Information Communities’ seman-tic schemas.

3.3.2. Technical foundations for OGIS

The Open GIS Specification is based on or related to several technologies including Object technol-ogy, Client-Server technology and Distribute Computing technology.

Object Technology

An object in software engineering is the representation or abstraction of reality. Object-orientation is a way of developing software that makes it for developers and programmers easier to convert entities from reality to computer representation. Open GIS Specification is based on object technology. Every feature on the earth is represented to objects. Among the characteristics of an object, those described below are of importance.

Encapsulation, one of the characteristics of object-orientation, plays a vital role in Open Geodata transactions.

Encapsulation is; the packaging of operations and data together into an object so that the data is only accessible through its interface; the mechanism that controls the modifications to the state of an ob-ject which include the changes to the object’s data.

Each object participating in data model includes all the operations and data needed to do a given set of tasks by means of encapsulation. Therefore, the integration of different object-oriented GIS sys-tems, or data exchange between them, or accessing distributed geodata and distributed geoprocessing means interoperability of the objects.

The other characteristic of object that must be addressed is the fact that objects can be accessed only through interfaces. Interface is a protocol with which different objects can communicate. Interface is an external description of an object that shows the responsibilities the object has towards other ob-


34

jects. The Open GIS Specification is trying to develop standard interface specification of an object model instead of internal implementation of an object. Through this standard interface specification different GIS systems can access to data implemented in other systems as shown in Figure 3 – 4. Polygon objects from both GIS systems have common interface, IGeometry, defined by Open GIS Specification. Both systems can access to objects implemented in other system through the IGeometry interface.

Figure 3-4 Polygon object in different GIS

Client – Server Technology

The Open GIS Service Model as proposed in Open GIS Specification exploits the general architecture of client-server configurations, in which “client objects” communicate with “service provider objects” requesting data or a processing function. Some client objects will access multiple service provider objects as well as service provider objects request service from other service provider objects. Access to a number of different spatial databases is an essential requirement to create an open geoprocessing environment, as the current user community demands are growing for distributed access to spatial da-tabases. Many general-purpose databases also contain address and coordinate data which may need to be integrated with a spatial database. Therefore the open geodata paradigm has to provide a common interface to a number of different database systems. Each database normally has its own tools and mechanism to ensure data integrity, security and ownership as well as data search and retrieval func-tions. In Open GIS Service Model, there are three main roles including Clients, Application Providers, and Data Providers. Both Clients and Service Providers use common interface, Open GIS interface, for communication with each other. In this circumstance, users don’t have to develop or purchase full-pledged application but identify requirements of application and carefully look for relevant compo-nents that meet requirements. The world of computing is moving towards componentware and net-work-based computing, and Open GIS interfaces make it possible for geoprocessing to be part of this progress.

Distribute Computing Platforms (DCPs)

The client-service architecture can only be implemented on a DCP (Distributed Computing Platform). In all client-server environments, a client makes a request for service to a service provider. The ser-vice provider then provides its service in a response. In the case of transactions between Open GIS Specification conformant clients and servers, client and server components’ interfaces conform to data types and software interfaces described in the Open GIS Specification. Those request-response mechanisms are referred to Distributed Computing Platform. (DCP) In order to achieve a smooth in-

Implementation

Polygon

GIS X

Envelope ( ) Contains ( ) Disjoint ( ) Intersect ( ) Overlaps ( ) Touches ( ) Polygon

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35

teroperability all the transactions between the client and service providers need to be performed under a common interface. Major Distributed Computing Platforms (DCPs) are listed below. • Common Object Request Broker Architecture (CORBA) from OMG • Component Object Model (COM) from Microsoft • Distributed Computing Environment (DCE) from OSF • Java from SunSoft, etc. Within a single DCP such as CORBA, common representation of the object format allows object in-terchange between systems and/or tools. But between DCPs is very difficult to communicate with each other and so it is left for future development. The technical Committee in OGC develops the Open GIS Specification as an Abstract (DCP-independent) Specification. Then OGC technology pro-viders develop DCP-specific Implementation Specification.

Figure 3-5 Open GIS Specification (adopted from OGIS topic 12)

3.3.3. Open Geodata Model

Open Geodata Model is a general and common set of basic geographic information types that can be used to model the geodata needs of more specific application domains, using object-based and/or con-ventional programming methods. (The Open GIS Guide, 1998) Open Geodata Model provides devel-opers with a comprehensive view that embraces common spatial reference system, geometry, feature, and meta data descriptions. It should be noted that Open Geodata Model is not a data transfer standard or data translation program that translates one data format to another. It is a software interface speci-fication for dynamically translating geodata from various sources into a single, comprehensive object based data model which can then be accessed directly from OGIS conformant applications.

Architecture of Open Geodata Model

Feature is the basic unit of digital geospatial information in Open Geodata Model. Feature is digitally coded abstractions of real-world objects and phenomenon that have a geometric representation and space/time and other attributes associated with them. Identification of feature depends on the applica-tion or interests of each Information Community. Feature is composed of three basic elements (The Open GIS Guide, 1998): Spatial components are composed of geometries, such as points, lines, polygons, grids and spatial ref-erence systems (SRS) defined by projections, coordinate systems and allowable transformations.

UML

Abstract Specification Implementation Specification

CORBA

OLE/COM

SQL

DCP neutral

UML

UML

UML


36

Semantic components define the object such as entity or phenomenon in terms of real world model using a Feature Dictionary or Attribute Schema. Metadata describes any additional information required to interpret an object correctly in the context of an information community.

Figure 3-6 The Open Geodata Model (adopted from OGC) Up to now most GIS software vendors have been focusing on develop common set of spatial compo-nents of geographic information. Some of them have been commercialized in the market such as Ora-cle8i SpatialTM, ArcGISTM, GeomediaTM, etc.

3.4. Business Process Reengineering (BPR)

Business Process Reengineering (BPR) is a matter of rethinking and redesigning (reengineering) the business process. As today’s business process is different from previous one the future business proc-ess is likely to be different from current one due to the changing environment. The organization must review the changing environment and make a decision of how the business process operates. BPR is the technique that provides systematic approach to changing the business process.

3.4.1. Definition of BPR

Michael Hammer is generally acknowledged to have defined the concept of business process reengi-neering. Hammer states that the rules have changed and organizations need to re-conceptualize their business processes. The definition of BPR defined by him is described below. "Reengineering is the fundamental rethinking and radical redesign of business processes to achieve dramatic improvements in critical, contemporary measures of performance, such as cost, quality, ser-vice, and speed". (Hammer M. & Champy J., 1993) According to this definition the most important objective of the BPR is to achieve dramati-cally improved performance of business process. The other well-known authority on BPR, Davenport defined the BPR as: "Reengineering is only part of what is necessary in the radical change of processes; it refers explic-itly to the design of the new process. The term process innovation encompasses the envisioning of new

OGIS Features

Metadata

Spatial Components

Semantic Components

Spatial Reference System

Geometry

FeatureCoverage

Feature Dictionary

Attribute Model

Point Line Polygon •••


37

work strategies, the actual process design activity, and the implementation of the change in all its complex technological, human, and organizational dimensions." (Davenport H., 1993) He stresses that BPR project manager needs to combine the concept of radical reengineering with the discipline of continuous process improvement.

3.4.2. Object – Oriented Business Engineering: BPR Methodology

To apply BPR concept into the business-reengineering project, consistent and systematic methodology must be used. Davenport H. (1993), Hammer M. and Champy J.(1993) proposed their own method-ologies. In this paper object-oriented business engineering methodology is studied. Object – oriented Business Engineering is one of the BPR methodology developed by Jacobson I. (1994). As summariz-ing this methodology, the reengineering directives initiate the reengineering projects. Once the reen-gineering project is initiated the first step is to make vision of the future business in conjunction with reversing the existing business. The result of envisioning is the statement of vision of the future busi-ness. Modeling new business is carried out in order to produce the model of the new business. After verifying the model new business is installed. Overview of object-oriented business engineering is viewed in figure 3 – 7.

Figure 3-7 Object-oriented Business Engineering (Jacobson I., 1994)

Reengineering Directives A directive starts the entire reengineering project (Jacobson I., 1994). The directive comes from either inside organization or outside organization or both. Hammer J. (1993) states that those reengineering directives should have ‘case-for-action paper’. The ‘case-for-action paper’ explains why the business must be reengineered. Key drivers forcing dramatic change in the NMAs are researched in chapter 2.

Developing Business Visions (Envisioning) The output of envisioning is the statement of vision of the future business. The vision statement is a description of what the business is to become, how it is going to operate, and what kinds of results are expected (Eriksson H. & Penker M., 2000) Creating a vision is one of the most challenging tasks un-dertaken by a team or organization. Davenport H. (1993) identifies what envisioning activity must do. Envisioning activity must: • Ensure that the goals of the reengineered business process fit with the organization’s overall

goals. • Seek to understand how the existing business functions. • Interview current customers to find out how to improve customer satisfaction. • Benchmark the leading organization. Hiatt J. (1995) suggests some basic steps to create an effective vision for the future business: Cast the reengineering team carefully; Define reengineering project scope and objectives clearly; Build pro-found knowledge in your team; Stand in the future; Create a principle-centered vision.

Engineering the New Business

Reversing the Existing Business

Engineering the New Business

Installing the New Business

Envisioning Reengineering Directives The Reengineered

Business


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Engineering new business is based on vision statement produced by envisioning activity. This step consists of four main activities: model the external view of the business process, model the internal view of the business process, build the information system that supports the new business process, and test the redesigned business process model. This step is more elaborated in next section, business process modeling using UML.

Installing the New Business Install the new business process into the organization is not easy work. While installing the new busi-ness process the other part of organization should not be disturbed. The new business process must be compatible with the existing process. To make sure that the reengineering project succeeds pilot pro-ject is carried out.

3.4.3. Critical Success Factors (CSFs)

More than half of early reengineering projects failed to be completed, and for this reason business process reengineering "success factors" have become an important area of study. Success factors are a collection of lessons learned from reengineering projects. Seven reengineering success factors have been introduced from benchmarking studies with more than 150 companies over a 24-month period. (Source from ProSci's 1998-1999 Reengineering Best Practices study) Top Management Sponsorship Business process reengineering typically affects processes, technology, job roles and culture in the business. There must be strong objections against the change. Top management is responsible for re-solving this problems and convincing people that the effort is essential to the business. Strategic Alignment There must be strong tie between BPR project goals and organizational strategy. All efforts must be endeavored to achieve overall organization objectives. Vision statement, identifying core business are the example of tasks in this category. Business Case for Change The motive of reengineering project must be clarified and maintained in shorter but clear form of ei-ther text or graphs or both. Hammer J. (1993) calls this ‘case for action’. It covers the critical points of the reengineering effort: the current state, what impact this condition has on customers, the drivers that are causing this condition to occur. what to do for it. Proven Methodology BPR project needs an approach that will meet the needs of the project and understandable to all par-ticipating members. Change Management Business Process Reengineering entails radical change to the organization. The structure of organiza-tion is reorganized to carry out new business process. People working in the organization are affected by reengineering. A complete change management plan is the critical success factor of BPR project. Line Ownership BPR project needs to involve line organization, people who have the ownership on the line operation, as well as expert from outside line operation in order to obtain comprehensive reengineering plan of line operation. Reengineering Team Composition The reengineering team should include all representative of stakeholders. Also the size of the team must be manageable.


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3.5. Object-oriented Business Process Modeling using UML

Business process modeling is the core part of BPR project, which creates an abstraction of a complex business and establishes a common understanding that can be communicated to the business’s stake-holders e.g., owners, management, employees, and customers. The central concept used for process modeling is the business process, which describes activities within the business and how they relate to and interact with the resources in the business to achieve a goal for the process. Davenport H. (1993) defines process like: “A process is a specific ordering of work activities across time and place, with a beginning, an end, and clearly identified inputs and outputs: a structure of action.” Defense of Department (DoD) in United States defines process compared with function. “A process is simply the largest unit referring to the flow of work through an enterprise beginning with external suppliers and ending with external customers.” “A function is a specified type of work applied to a product or service moving within a process.” As summarizing those definitions of process, business process is initiated by external stakeholders such as customers, suppliers and executed by internal objects with various resources in order to achieve the goals imposed to the business process. Figure 3 – 8 shows the definition of business proc-ess in schematic way.

Figure 3-8 Business Process Architecture

A good process model has the following characteristics (Eriksson H. & Penker M., 200) • Captures the real business as truthfully and correctly as possible. • Focuses on the key processes and structures of the business at an appropriate level of abstraction. • Represents a consensus view among the people operating in the business. • Adapts easily to change and extensions. • Easy to understand and fosters communication among the different stakeholders of the business.

3.5.1. Use –Case driven Business Process Modeling

Use – Case driven approach to system engineering was proposed by Jacobson I. et al in 1992. The approach was adopted in order to apply it to business engineering. When modeling the business proc-ess two types of model must be produced: external and internal. The external model of the business is called a use-case model. The use-case model describes the in-teraction between external environments and the business process. The use-case model identifies that

Business Process

Goals

User Re-quire ments

Human Object

ResourceObject

User Wishes

Executed Use

Achieve


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what the system must provide to the actor; what the business will do to achieve user satisfaction. In the use-case model one use-case represents one business process. In most cases several use-cases are related each other so that the relationship between use-cases must be clearly described. The internal model describes that how the business is run, how the use-case is realized to perform its purpose, what are the participating objects, their relationships, and interactions between them. The internal model is divided into two types of model: information system, object model. Modeling infor-mation system that supports the business is very important part of business process modeling. The term Information system in this thesis is used such that the information about the objects participating in the business process are defined and stored in the information system. The object model describes the behavior of the objects in the business process. This model can verify the use-case model and in-formation system. The model of the business process is tested by simulation or prototyping. In this research UML is used for modeling. Refer to appendix A for more information about UML. Overview of use – case driven business process modeling is shown in figure 3 – 9.

Figure 3-9 Overview of Object-oriented business process modeling (Jacobson I., 1994)

3.5.2. The Use – Case Model

A primary purpose of the Use –Case model is to describe how the business is used by its customers and partners, so called business actors. That is why it is called external view of the business. It de-scribes the interaction between the business process and external environments. Vision statement pro-vides the basis on which the use-case model is built so that the model of the business process fits with the vision of the business. The Use – Case model consists of three elements: actors, use-cases, and system boundary. The Use – Case model designates the scope of the reengineering project, that is sys-tem boundary, by describing actors and use-cases.

3.5.2.1. Identification of Actors

Identification of actors is the activity to find the people or things that use the business process. An actor represents not the person who interacts with the system but the role that the user or users play while interacting with the system. Therefore the name of actors should reflect its role towards the business. One thing that should be kept in mind is that all actors must be identified within the scope of the reengineering project. To make sure that all actors are identified the activity of identification of actors is iterated while defining use-cases and describing the relationship between use-cases and ac-tors until all necessary actors and use-cases are identified and modeled. Another important thing is that none of the actors is inside the business process. By keeping those two things in mind during identifying the actors the exact system boundary can be identified.

Strategic ObjectivesProcessSpecificationVerification of models

Use-case Model

Object Model

Information Model


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Each actor has a name and description. As explained earlier the name of each actor must represent the role that the actor plays while interacting with the business. This name must be explicit for all partici-pants in the reengineering project. Description of each actor includes the responsibility or role of the actor to the business and the way to interact with the business. In UML the actor is represented by stick man shown in figure 3 – 10.

Figure 3-10 Actors and System boundary

3.5.2.2. Use-Cases

A Use-Case represents a business process that is defined in the early part of this section. I. Jacobson introduced use-case approach for software engineering in 1992. Afterwards the use-case approach is extended to the area of business engineering (Jacobson I., 1994). The term use-case means the way in which a user uses the business process. Each use-case in the model must have interaction with the ac-tors otherwise it must be removed from the model. Modeling use-case involves several steps including identification of use-cases, associations between use-cases, description of each use-case, association between actors and use-case. Identification of Use-Cases Jacobson I. (1994) defines the use-case as: A sequence of transactions in a system whose task is to yield a result of measurable value to an indi-vidual actor of the system. Within the scope of reengineering project all tasks that the system is supposed to do are the candidates of the use-case. Each use-case has a name indicating what the system will do for the actors. After identifying all possible use-cases each use-case is linked to corresponding actors. If there is a use-case that does not have association with any actors the use-case must be removed from the model. Associations between use-cases A business reengineering project may have many use-cases. To make the model comprehensive and explicit some techniques are used to structure the use-cases. Extends and uses association is widely used both in software and business engineering. Description of a use-case Each use-case has a description that contains name, corresponding actors, and flows of events, alter-natives. The flows of events can be described in text or diagram. An activity diagram in UML illus-trates the flow of events of a business use-case. Activity diagram is useful to identify business objects that are participating to the use-case. Association between actors and use-case

System

Actor2Actor3


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The association between actors and use-case is refined during the use-case modeling. If there is actor or use-case that does not have association the model has something wrong. All actors and use-cases must at least have one association in the model.

3.5.2.3. An example of the Use-Case Model

Figure 3 – 11 shows an example of the simple Use-Case Model of TopoMap Production System. As shown in the diagram the actors are not necessarily to be outside of the organization but other parts of the organization that are not participating in the reengineered project in this case distribute department and marketing department could be actors. The use-case satellite image acquisition is to be carried out in the condition that satellite image is the raw material for the topoMap production system. PaperMap Reproduction use-case is taken out from the base use-case because this use-case can appear in differ-ent business processes. This structure can help to reuse the use-case in several times.

Figure 3-11 An example of a Use Case Model

3.5.3. Information model

Information model contains all information about the objects participating in the business. A business use-case can be described by showing which objects are involved in the use-case, and how these ob-jects are related to one another. Objects contain information (attributes) and behaviors (operations) which are necessary to fulfill the responsibility in the use-case. Information model usually starts with drawing activity diagram with swimlane and object flow. By showing individual activities business objects can be identified easily.

3.5.3.1. Concept of Business Objects

In business process modeling two kinds of objects are identified and described: business worker and business entity (UML Specification Version 1.4 draft, 2001). Business worker in turn is subdivided into two types: internal worker and case worker called interface object and control object respectively

Satellite ImageAcquisition

Produce TopoMap

Distribute Dept.

TopoMap Production System

Marketing Dept.

Satellite Image Supplier

«extends»

PaperMap Reproduction

«uses»


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in Jacobson I. definition (1994). This research follows I. Jacobson’s terminology in modeling step. Business worker is the abstraction of the person who takes certain role in the use-case. Business entity is the thing that is handled or used by business workers in order to achieve the goal of the use-case. Finding the business objects that are participating the use-case is critical for the success of the reengi-neering project so that the reengineering team must be carefully organized to be able to collect all necessary objects. In early stage of finding objects the Class Responsibility Collaborator (CRC) card developed by Beck K. & Cunningham W. in 1980’s is widely used. In CRC card the candidate classes are described with its responsibility and other objects with which the class is collaborating. The re-sponsibility can help to define the attributes and operations of each object. The collaborator can be used to define the associations between objects. The classes that are identified by CRC card are more elaborated during modeling procedure.

3.5.3.2. Characteristics of Business Objects

In information model each object belongs to a class that has the same type of information. Each object is an instance of the class. The object can be distinguished by the unique value of information. The information linked to class is its name, attribute, and operation. The name of each class must be unique and well describe what role the class is playing in the use-case. Attribute is the quality or property of the class. It shows the state of the class at a certain moment. Operations are the acts per-formed by the class. In UML class diagram a class is drawn with rectangle that is divided into three compartments. Name, attributes, operations is described respectively from top compartment to bottom.

3.5.3.3. Relationships between Objects

A class diagram in UML shows the static structure of the business use-case by showing the business objects and relationships between them. There are three important relationships between business classes: generalization, aggregation, and association. Generalization indicates that one class inherits from other classes. With generalization-relationship the attributes and operations of one class can be re-used by others. Aggregation is useful when one class is composed of other class or classes and the composed class has to be handled as a single class. Association represents that one class has connec-tion with another class. Each association has a name and multiplicity. Multiplicity shows how many objects from both classes are participating in each association.

3.5.4. The Object Model

While information model shows the internal structure of the business the object model shows the in-ternal behavior of the business. To achieve the goal of each use-case the objects in the use-case inter-act each other. In UML interaction between objects are described in sequence diagram.

3.5.4.1. Interaction diagrams

Interaction diagram shows the interactions that take place between the objects during a use-case’s flow of events (Jacobson I., 1994). Sequence diagram in UML is used for the interaction diagram. For the sake of clarity a use-case may have several interaction diagrams each of which shows one flow of events in a use-case. A use-case is more precisely described or explained by showing the interaction between participating objects in the use-case. Interaction diagram is based on a use-case model and information model. Feedback from interaction diagram goes back to the use-case mdoel and informa-tion model. This iterative procedure continues until the whole model is completed.


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3.5.5. Verification of Business model

Before installing the model of new business it must be verified. Simulation and prototyping are well-known techniques for testing process models. Simulation is the technique to predict the consequence of implementation of the new business process before implementing it. Simulation can help to compare alternative models in terms of various per-formance indicators. Computer simulation offers powerful analytical tools based on accumulated sta-tistics. Prototyping is useful to test feasibility of the processes that are supported by information technology (IT). The output of the prototype can be evaluated whether it fits to the purpose and conforms to the specification. This verification activity is carried out throughout the BPR project. The result of verification is fed back to the models and then used for refinement of the models again. After a number of iteration com-plete model of new business is built.


Geographic data has been collected in digital form for more than 30 years. During this period, many different methods for acquiring, storing, processing, analyzing and viewing geographic data have been developed, mostly independently from one another. Proprietary data from different vendors hinder data sharing and deprive data users of freedom of the data and application selection. Open GIS Specification establishes a common technology foundation on which the software industry can build interoperable geoprocessing applications and software components. The Open GIS Specifi-cation consists of three parts: Open Geodata Model, Open GIS Service Model, and Information Community Model. Among them Open Geodata Model is the core of the others. It provides common data model that enables transparent data sharing and geoprocessing operations on the data. It is an obvious fact that major geodata providers in the world, including software vendors, are participating the Open GIS Consortium (OGC) and trying to produce OGC compliant software in order to increase market share. Object-oriented business engineering is one of the BPR methodologies. It gives comprehensive ap-proach to redesign the business process. Among the BPR project activities process modeling is the core part. According to the definition of business process it has external and internal aspect. In use-case driven business process modeling use-case model describes external view of the business process while information system and object model describe the internal view of the business process. By de-scribing both external and internal model of the business process the questions what the business must do and how the business operates are explained. UML is a modeling language that can be used to de-pict all models from use-case model to information system and object model.


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4. Redesign Topographic Mapping System

4.1. Introduction

The objective of this chapter is to provide a guideline for object-oriented business process modeling often called use-case driven business process modeling. This corresponds to ‘engineering the new business’ step in object-oriented business engineering proposed by Jacobson I. (1994). Use-case driven business process modeling has two perspectives: external perspective and internal perspective. External perspective of business process is modeled by use-case model. Internal perspective is mod-eled by information model and object model. This chapter begins with proposed system architecture in which objectives of topographic mapping system and conceptual architecture are introduced. In section 4.3 to 4.5 use-case model, information model and object model are explained respectively.

4.2. Proposed System Architecture

In chapter 2 critical analysis about topographic mapping system has been carried out. The chapter covers evolutionary stages and current situation of national mapping agency, business driving factors and challenges, and advantages of new information technologies. From this analysis, strategic objec-tives of the topographic mapping system and conceptual architecture of the system are derived.

4.2.1. Strategic objectives of topographic mapping system

Strategic objectives are identified to provide the direction where the system has to step forward to achieve the aims of the system. Aims of some advanced NMAs are referred to identify strategic objec-tives for the new topographic mapping system. • To satisfy the national interest and customer need for accurate and readily available geospatial

data and maps of the whole of the Great Britain in most efficient and effective way (Source from Framework of Ordnance Survey (OS) in UK).

• To ensure that Australia derives economic and social benefits from access to fundamental geo-graphic information through partnership with industry and government (Source from Strategic plan of National Mapping Division of Geoscience Australia).

• To provide the Nation with current, accurate, and nationally consistent basic spatial data, includ-ing digital data and derived topographic maps, and deliver spatial information that is not more than seven days old (Source from The National Map of USGS).

To achieve these aims, strategic objectives of topographic mapping system can be identified as fol-lows: • Maintain the national topographic database which complying with Open GIS Specification, is up-

to-date and of suitable quality to meet the current and future needs of a wide range of customers. • Provide nation wide medium and small-scale topographic maps


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• Produce diverse products and services to meet the customers’ needs

• Make available web topographic mapping for data access, retrieve and manipulate • Increase efficiency and productivity throughout the system by adopting new information technol-

ogy

4.2.2. Conceptual Architecture of proposed topographic mapping system

Topographic mapping system proposed in this research can be divided into four main components: production processes, service processes, workflow, and geodatabase management system. Both pro-duction and service processes are communicating with database through the workflow interfaces. Data from various production processes are stored and maintained in database for both service processes and other production processes. In this system architecture, the full extent of internal data exploitation and product diversity become possible. The topographic database in this model complies with Open GIS Simple Feature Specification for SQL (SFS/SQL). The requirements of these components come from analysis about user requirements, information technologies, GIS market, institutional con-straints, etc. Figure 4 –1 shows conceptual architecture of proposed topographic mapping system. The

term use-case is used for the process because each process is identified as use-case in modeling step. Figure 4-1 Conceptual Architecture of proposed topographic mapping system

4.2.2.1. Production processes

Production processes component is an internal business process of topographic mapping system. Ba-sic goals of production processes are to produce foundation data such as topographic template, DTM,

TopographicMaps

AerialPhotographs

SatelliteImages

ProduceTopographic DB

Web MappingService

Customerdemand product

Delivery

Standard ProductDelivery

Hardcopy MapProdcution

ProduceGeodetic control

ProduceGeographic

mane

ProduceDEM

ProduceOrthoimagery


Contractor

Mandated Client

General Customer

Internet User

Prod

uctio

n W

orkf

low

Inte

rfac

e

Serv

ice

Wor

kflo

w In

terf

ace

Production Use-CaseRequirements

User Requirements, Information Technology, GIS Market, Institutional constraints, etc.

Geodatabase RequirementsService Use-Case

Requirements

Metadata

Hardcopy MapArchives

Digital ProductsArchives

TopographicDB

Source dataArchives

Workflow Requirements


47

orthoimagery, geographic name, geodetic control, etc. The products from each production process are stored in enterprise wide database management system so that they can be delivered as final products or sent to other production processes. Although there seems to be no direct link between business process and external customers all individual processes are strongly influenced by customer’s re-quirements.

4.2.2.2. Service delivery processes

Service delivery processes component is an external business process of topographic mapping system that is interacting with external customers. Standard products are to be delivered by predefined proce-dure. Customers can be served specific type of products by ‘Customer demand products supply’ proc-ess. Spatial data stored in topographic database can be accessed, retrieved, and manipulated through the Internet. All service delivery processes communicate with enterprise wide database management system for their own purposes.

4.2.2.3. Geodatabase management

Topographic mapping system needs to manage spatial data for internal and external use. The data that are going to be stored and managed in geodatabase management system are selected by investigating user requirements and internal data exploitation. Geodatabase management involves data storage, data access and security, data maintenance, data update, and metadata management. A systematic approach to geodatabase management must be ensured in order to be able to make the best use of spatial data.

4.2.2.4. Workflows

Workflow component is a bridge that connecting business processes to geodatabase management sys-tem. Data from each business process are sent to geodatabase management system to be stored and brought from geodatabase management system for various purposes through workflow. Workflows enable to access geodatabase from GIS tools that are used for production processes and service deliv-ery processes.

4.3. Business sub-systems for topographic mapping system

When modeling large system like topographic mapping system it is often desired to model the system in different level of detail (Jacobson I., 1994). From proposed system architecture defined in section 4.2, three main sub-systems such as production system, geodatabase management system, and service delivery system are identified. For each sub-system there are actors and use-cases to achieve the aims of the sub-system. In this thesis production system and service delivery system are modeled in detail because both systems are considered as core business processes that are regarded as essential for pro-vision of products to customer (Radwan M. M. et al, 1999). Figure 4 –2 shows topographic mapping system and its sub-systems. The use-case models that refine production system and service delivery system are modeled in section 4.4 and 4.5 respectively.


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Figure 4-2 Topographic mapping system and its sub systems

4.4. Models for production system

In object-oriented modeling there are two perspectives from external and internal. Use-case model describes external perspective of the system. Information model and object model describe internal perspective of the system. In this section production system are modeled. From use-case model one use-case, that is ‘Create Topographic DB’ use-case, is chosen to produce information model and ob-ject model.

4.4.1. Actors and use-case model

Business use-case model shows external view of the production system by identifying actors and use-cases. From the proposed system architecture defined in section 4.2 the model of production system is produced as shown in Figure 4-3. This model explains what the system must do by use-cases and who uses the system by actors. Identifying actors and use-cases is the first step to model the system. An actor represents a role that someone or something in the external environment can play in relation to the business process (Jacob-son I., 1994). There are many users of production system. These users are classified into the actors in terms of the role they play in relation to the system. A use-case represents a business process that is defined in chapter 3, section 3.5. Every actor and use-case should have at least one association to each other.

Geodatabasemanagement system

Service delivery system

Production system

Topographic MappingSystem

use-case1

«refines»

use-case2

use-case3

«refines»

«refines»

use-case7

use-case8

use-case9

«refines»

«refines»

«refines»

Productionsystem

Geodatabasemanagement

system

Service deliverysystem

use-case4

use-case5

use-case6

«refines»

«refines»

«refines»


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Figure 4-3 Use Case model of production system

4.4.1.1. Identification of actors

a). Contractor Contractor represents private individual whom national mapping agencies supply products and ser-vices by making a contract. b). Mandated Client Mandated Client represents public authority whom national mapping agencies supply products and services by the legislation. c). General customer General customer represents individual who order standard products or user-specific products. d). Internet user Internet user represents individual who access to national mapping agencies, order and receive prod-ucts through the Internet. e). Satellite image supplier Satellite image supplier represents a company who is to supply satellite images to national mapping agencies by making a contract.

4.4.1.2. Identification of Use-Cases

a). Produce Topographic DB Produce Topographic DB use-case produces topographic database for national coverage. This use-case can be divided into two sub use-cases: Digital Data Acquisition and Create Topographic DB.

Production system

Produce Topographic DB

Produce DEM

Produce Orthoimagery

Produce Geographic name

Produce GeodeticControl

Hardcopy mapproduction


Mandated Client

Internet User

Contractor

General Customer


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Digital Data Acquisition Digital Data Acquisition use-case produces digitalized topographic data from various source data. There are three main variants according to data sources such as scanned map, aerial photographs, and satellite images. Inputs of this use-case are specifications for product, data source, and field survey. Outputs of this use-case are digitalized data for example DXF file and digital source data such as geo-referenced aerial photographs, satellite images, and scanned topographic maps. Create Topographic DB Create Topographic DB use-case produces national topographic database. Inputs of this use-case are digitalized data from Digital Data Acquisition use-case and topographic database specification. Out-put of this use-case is a national topographic database. b). Produce Orthoimagery Produce Orthoimagery use-case produces orthoimagery. Inputs of this use-case are source photos and source digital elevation model. Output of this use-case is defined format of orthoimagery. c). Produce DEM Produce DEM use-case produces Digital Elevation Model (DEM) from aerial photographs or stereo pair of satellite images. Inputs of this use-case are triangulated stereo model, parameter files and to-pographic data. Output of this use-case is defined format of DEM. The goal of producing a DEM is either a final product or the input to some other process such as relief layer in topographic database, orthoimagery production. d). Produce Geographic name Produce Geographic name use-case produces information about physical and cultural geographic fea-tures in country. e). Produce Geodetic Control Produce Geodetic Control use-case produces geodetic control on whole country. The outputs of this use-case are triangulation station coordinates and GPS station coordinates. f). Hardcopy Map Production Hardcopy Map Production use-case produces various kinds of analogue maps such as topographic map and thematic maps. This use-case has two main variants: standard products and customer demand products. Inputs of this use-case are topographic database and map specification. Outputs of this use-case are analogue topographic map and various kinds of thematic maps.

4.4.2. Workflow activities: Activity diagram

4.4.2.1. Text description of use-case workflow

Produce Topographic DB use-case is divided into two sub use-cases: Digital data acquisition use-case and Create Topographic DB use-case. In this paper only the latter use-case is modeled. Use-case is described by basic flow of events that is called scenario and possible alternatives. Goal of use-case: Created new table in topographic database from digitalized data Actors: Mandated Client, Contractor, General customer, Internet user, Satellite image supplier Scenario (Basic flow of events) Step 1. Project manager prepares project plan. Step 2. Project manager assigns work orders to each operator


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Step 3. Edit operator retrieves digitalized data from source data archive. Step 4. Edit operator restructures the digitalized data into different themes. Step 5. Edit operator identifies and defines geometry type and attributes for each feature according to database specification. Step 6. Edit operator builds and cleans topology between features. Step 7. Edit operator edits attribute data. Step 8. Edit operator checks topological integrity within and between layers. Step 9. Edit operator merges adjacent area. Step 10. Edit operator validates geometric, topological, and attribute integrity. Step 11. Edit operator loads spatial data into the topographic database. Step 12. Edit operator reports to project manager Step 13. Database operator checks topographic database integrity Step 14. Database operator reports to project manager. Alternative 4 (Condition: the number of thematic layers > 1) Step 4 is repeated the same number of times as the condition. Alternative 8, 10,13 (Condition: the result is not acceptable.) Step 8-1. Correct the problems and go back to Step 8. The same step is applied to step 10-1, 13-1.

4.4.2.2. Activity diagram

Before identifying business objects it is desired to draw activity diagram showing workflow of a use-case. In this research swimlanes in activity diagram represent business workers who are responsible for the activities inside the swimlane. The activity diagram of Create Topographic DB use-case is shown in Figure 4 – 4.


Business workers that are participating in Create Topographic DB use-case are: project manager, edit operator, and database operator. Business entities are: project plan, work order, digitalized data, theme, topographic database, and spatial layer. Both edit operator and database operator are con-strained by business rules that they report to project manager when preconditions are satisfied. Figure 4 – 5 shows information model of Create Topographic DB use-case. Each business object contains attributes and operations that are necessary to fulfill their responsibility in the use-case. Some objects appear more than one information model. In this research topographic database appears in both information model of Create Topographic DB and Customer demand product delivery use-case. It should be noted that the class definition of topographic database in both model must be the same.


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Figure 4-4 Activity diagram of Create Topographic DB use case

Database operatorEdit operatorProject manager

Prepare project plan

Assign work to edit operators

Retrieve source data

Restructure the data

Identify geometry type

Build and clean topology

Edit attribute information

Check topological integrity

[Unacceptable result]

[Acceptable result]

Correct the problems

Merge adjacent data

Validate geometry, topology, attribute

[Unacceptable result]

Correct the problems

[Acceptable result]

Load data into topographic database

Check database integrity

Report to the project manager

[Unacceptable]

[Acceptable]

Correct problems

Create work order

Report to project manager


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Figure 4-5 Information Model of Create Topographic DB use case

4.4.4. Object model

A use-case is more precisely described and explained by showing the interaction between participat-ing objects in the use-case. In information model all objects and their relationships each other are identified and modeled. Object model can express in more detail how the various objects in the model interact to execute a certain flow of events. In this research sequence diagram in UML is used for ob-ject model. Figure 4 –6 shows object model of Create Topographic DB use-case. Project manager interacts with project plan, work order, edit operator, and database operator. Edit operator interacts with work order, digitalized data, theme, and topographic database. Database operator interacts with work order and topographic database. Topographic database interacts with spatial layer. For the sake of simplicity the interaction mentioned before are not included.

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inform work completion

Inform work completion


54

Figure 4-6 Object Model of Create Topographic DB use case

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55

4.5. Models of Service delivery system

In this section service delivery system is modeled. Among use-cases of this system Customer demand product delivery use-case is chosen to produce information model and object model.

4.5.1. Actors and use-case model

Figure 4 – 7 shows use-case model of service delivery system. As shown in the model actors of ser-vice delivery system are the same as the actors of Create Topographic DB use-case excluding Satellite Image Supplier. There are three use-cases such as standard products delivery, customer demand prod-uct delivery, and web mapping services in this system.

Figure 4-7 Use case model of service delivery system

4.5.1.1. Identification of use-cases

a). Standard Product Supply Standard Product Supply use-case provides products to the contractors and mandated clients by the contracts or the legislation. Input of this use-case is distribution plan. Output of this use-case is stan-dard products supply. b). Customer demand Product Supply Customer demand Product Supply use-case handles general customers who are not contractors or mandated clients. This use-case is initiated by customers by submitting an application. This use-case is extended by Hardcopy Map Production use-case and various digital products production process in the case where new products are needed. Inputs of this use-case are user’s application, a standard product list, and metadata. Output of this use-case is user defined products supply. c). Web Mapping Services Web Mapping Services use-case handles Internet users by publishing spatial information on the web site. Inputs of this use-case are topographic database and metadata. Outputs of this use-case are prod-ucts and services to the Internet users.


Standard ProductsDelivery

Customer demandproducts delivery

Web mapping services

Contractor

Mandated Client

General Customer

Internet User


56

4.5.2. Workflow activities: Activity diagram

In this paper ‘Customer demand product delivery’ use-case is chosen for further modeling.

4.5.2.1. Text description of use-case workflow

‘Customer demand product delivery’ use-case handles general customers who are not contractors or mandated clients. This use-case is initiated by customers by submitting an application. Goal of use-case: To provide customer defined product Actors: General Customer Scenario (Basic flow of events: DEM production) Step 1. Customer submits an application to customer handler Step 2. Customer handler examines the application and check standard product lists Step 3. Customer handler creates possible product specifications Step 4. Customer conforms his/her application Step 5. Customer handler delivers selected product specification to GIS operator Step 6. GIS operator examines product specification Step 7. GIS operator accesses to topographic database Step 8. GIS operator queries and retrieves the area defined by product specification Step 9. GIS operator creates the product in defined format Step 10 GIS operator informs order handler that the product is available Step 11. Customer handler checks payment Step 12. Customer handler informs delivery center delivery work Step 13. Delivery center delivers the product Alternative 2. (Condition: Customer wants standard product) Step 2-1 Customer handler offers the product and gets payment This use-case is finished. Alternative 4. (Condition: Customer cancels application) This use-case is finished. Alternative 5. (Condition: the product is hardcopy map) This use-case is extended to Hardcopy Map Production use-case. After completing Hardcopy Map Production use-case workflow comes back to Step 11 in basic flow of events. Alternative 6. (Condition: data is not available) Execute Produce DEM use-case. After completing all activities in Produce DEM use-case workflow returns to Step 9.

4.5.2.2. Activity diagram

The activity diagram of ‘Customer demand product delivery’ use-case is shown in Figure 4 – 8.


57

Figure 4-8 Activity diagram of Customer demand product delivery use case


Business workers that are participating in Customer demand Products Supply use-case are: customer handler, GIS operator, and delivery center. Business entities are: application, standard product list, standard product, product specification, topographic database, working data, DEM product, and deliv-ery work. Some operations of customer-handler class are constrained by business rules respectively. Associations between delivery-work and standard product, delivery-work and DEM product depend on the value of standard-product attribute of Application class. Figure 4 –9 shows information model of Customer demand product supply use-case.

4.5.4. Object model

Figure 4 –10 shows object model of ‘Customer demand product delivery’ use-case. This use-case is initiated when customer submits an application. Customer is not a business object in this model. Cus-tomer handler is an interface object that interacts with actors. In this model alternative lifelines are used to show different flow of events according to condition. For example if customer refuses the pro-posal that are made by customer-handler flow of event goes directly to the end of customer-handler’s lifeline without executing the rest of the flow of events.

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Get conformation

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58

Figure 4-9 Information Model of Customer demand product delivery use case

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59

Figure 4-10 Object Model of Customer demand product delivery use case

«Interface object»Customer handler

«Entity object»Application

«Entity object»Standard product list

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[Customer refuse proposal]


60


In this chapter two tasks, proposal of system architecture and development of models for the proposed system, have been discussed. Conceptual system architecture has been proposed with strategic objec-tives. The proposed system is an integrated system that is composed of business processes, data man-agement, and information system. Each business process can connect to database management system through information system. Conceptual system architecture proposed in this chapter shows how each of components is integrated to achieve objectives of the system. Full exploitation of internal data and products diversity become possible. Models that describe topographic mapping system have been developed in this chapter. Use-case model explains external view of the system that is what the system must do and who uses the system. Information model shows participating objects and static relations between the objects within use-case. Object model shows how the objects interact. Object-oriented model including these three mod-els provides comprehensive and understandable view of the system: external and internal model, static and dynamic model.


61

5. Verification of the proposed system

5.1. Introduction

In the previous chapter 4, the conceptual architecture of topographic mapping system was proposed. The proposed system was modeled by using UML consisting a series of different models such as use case models, Information models, and Object models. It is very important to ensure that these models are well verified at an early stage (Jacobson I., 1994). In object-oriented business modeling a number of iterations between model development and verification are required. In this chapter, the models are verified by answering to assessment questions (or indicators). These questions refer to use-case model, information model, and object model. Due to limited time only in-formation model and object model from ‘customer demand product delivery’ use-cases is tested. In section 5.3, functional requirements of the proposed system is tested by implementing some part of the proposed system in commercially available GIS software complying with Open GIS Specification.

5.2. Verification of the models

Assuring total quality in a modelling effort involves the measurement and assessment of a variety of quality characteristics such as accuracy, execution efficiency, maintainability, portability, reusability, and usability (human-computer interface) (Balci O., 1998). In this thesis, only accuracy in terms of consistency of the models is considered to be tested. Computer Aided System Engineering (CASE) tools provide the capability of automatic consistency check. Sometimes CASE tool cannot find out inconsistency problem in the models because of insufficient information. Therefore, assessment ques-tions (or indicators) developed by Carr J. T. and Balci O. (2000) are introduced to test the different models produced during modeling procedure. These assessment questions are based on principles of Verification, validation, and accreditation (VV&A) established by Balci O. (1998). The principles are given in appendix B.

5.2.1. Object-oriented modelling life cycle

In Object-oriented modeling development approach, different models are produced in common model-ing platform (Carr J. T. and Balci O., 2000). It gives significant advantages to trace the faults from different models. Figure 5 – 1 shows object-oriented modeling life cycle encompassing different mod-els for different purposes. Although this life cycle seems to be sequential procedure, basically every step is subject to be iterated. When an inconsistency is found in any model, it can be traced back to the model in which the problem originated. The arrows from previous models to next models in the diagram show the track of the transformation of the objects. This is what is called traceability. Object-oriented modeling approach provides the ability to trace the objects forward and backward. Therefore, the defect found in later stage of model can be traced back to the model where it was firstly intro-duced. This section reviews object-oriented modeling life cycle with various kinds of verification techniques.


62

After determining system boundary with actors and candidate use-cases, use-case diagram is pro-duced. Each use-case represents a single use (or requirement) of the system. It has goals, actors, and sets of transactions. Each use-case is described in text and diagram (step 1). Brainstorming is the most frequently used technique to perform this step.

Figure 5-1 Object-oriented modeling life cycle Workflow of use-case described either in text or diagram is modeled in information model by identi-fying participating objects (step 2). Role-playing is often used to verify consistency between descrip-tion of use-case and information model. Role-playing means that each member of the group is as-signed a role, in other words an actor or an object that is participating in the system and they act as business actors, interface objects, control objects, and entity objects. The group then walks through how the system is used and who is responsible for what. Another technique often combined with role-playing is Class-Responsibility-Collaboration (CRC) cards. Classes and relationships modeled in in-formation model are reviewed by CRC card. Each CRC card represents responsibilities and collabora-tors of one class. Responsibility is mapped to attributes or operations of class. Collaboration is mapped to relationship with other classes in information model. Role-playing with CRC card can be used to model information model from description of use-case and to verify whether information model is consistent with use-case or not. Each unit class is tested according to their responsibilities and collaborations. Behavioral aspect of use-case is modeled in object model by showing interaction between objects (step 3). Object model is very useful to clarify and display the responsibility of each object. The other usefulness of object model is that it can show how the use-case’s flow of events interacts with the par-ticipating objects (step 4). Object model provides overall responsibilities and collaborations of indi-vidual object. Responsibilities correspond to attributes and operations in information model and inter-actions in object model. Collaborators correspond to classes having relationship with certain class in information model and objects being interacted with certain object in object model. Integration of

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63

class is tested in this step. Consistencies between object model and information model, object model and use case are checked.

5.2.2. Introduction of Assessment Questions (or Indicators)

At this moment assessment questions have been developed to test accuracy of use-case model, use-case, class diagram, sequence diagram (Carr J. T. and Balci O., 2000). The answer is ‘YES’ or ‘NO’. Although an answer for certain question is ‘NO’, it does not mean that the model is incorrect. Accord-ing to ‘principles of verification, validation, and accreditation (VV&A)’ developed by Balci O. in 1998 the answers to these questions should not be considered as a binary variable where the model is absolutely correct or absolutely incorrect. It indicates that there is a need for evaluation criteria of as-sessment results to judge accuracy status of the models. As mentioned earlier, at this moment only four sets of assessment questions have been developed. They are use case, use case diagram, class diagram, and sequence diagram. As principles of VV&A say, errors should be detected as early as possible in the modeling life cycle. These four modeling products are usually common in any type of object-oriented system modeling and appear early stage in the modeling cycle. This assessment questions were tested through software systems in Department of Defence (DoD) in United States (Balci O., 2000).

5.2.2.1. Assessment Questions for Use Case diagram and Use Case

• Use Case 1. Is the use case diagram drawn using a standard template? 2. Do actors and use cases follow a standard naming convention and format? 3. Are the actors external to the system? 4. Are the actors external to use case boundary? 5. Does an action by a user start each use case? 6. Is the start of each use case unambiguous? 7. Does the use case make sense? 8. Does the use case accurately represent the behavior specified in the requirements? 9. Does the use case cover all paths including decisions, alternates, and exceptions? 10. Are the preconditions correct? 11. Does the use case produce useful and appropriate results, i.e., are the post conditions correct? 12. Are the requirements captured by the use case specified? 13. Should similar use cases be combined into a single use case? 14. Should the use case and associated requirements be divided into several requirements and use

cases? 15. Is each functional requirements associated with at least one use case? 16. Are use cases sharing one or more functional requirements consistent? 17. Can the use case be tested?

• Use Case Diagram 1. Is there a use case diagram for each use case? 2. Are all use case diagrams drawn using the same, preferably the UML diagramming notation? 3. Is each actor represented in the use case diagrams in which it is involved?


64

4. Should similar use case diagrams be combined using use case associations such as extension of a use case and the use of a use case by another?

5.2.2.2. Assessment Questions for Class diagram

• Class Diagram 1. Is the class diagram drawn using UML? 2. Do all sequence diagram objects have associated classes in the class diagram? 3. Are design patterns used to create associations for common relationships? 4. Are there classes other than containers for which there are no corresponding objects in the

class diagram? 5. Are classes present not traceable to the requirements or use cases? 6. Are roles identified? 7. Are redundant classes present? 8. Are multiplicities shown and correct?

5.2.2.3. Assessment Questions for Sequence diagram

• Sequence Diagram 1. Are the sequence diagrams drawn using a consistent, preferably UML, notation? 2. Is there a use case from which the sequence diagram derives? 3. Is there an actor that initiates each sequence diagram the same one that initiates the use case

from which it is derived? 4. Are all nouns, noun phrases, and verbs that imply creation represented as objects? 5. Does the diagram have a meaningful termination? 6. Do all of the objects present in the sequence diagram have associated classes in the class dia-

gram? 7. Do the diagrams include alternatives and exceptions?

5.2.3. ‘Customer demand product delivery’ use-case

To answer the assessment questions, the model must be precisely tested with respect to unit object and interactions of objects. Enterprise Architect (EA) developed by Sprax systems Ltd. introduces 5 levels of test: unit, integration, system, acceptance, and scenario test (EA user guide). In this research, unit and integration test are carried out because unit test is suitable for information model and integra-tion test is suitable for information model and object model. System test is carried out in section 5.3.

5.2.3.1. Unit and integration Test

In this model ‘customer handler’ object is selected as an example of testing accuracy of information model and object model. This test is carried out to all objects and interactions in the models. ‘Cus-tomer handler’ object is an interface object that interacts with outside the system, in other words, the actors. Interface object often has coordinating responsibility in the use-case according to conditions. ‘Customer handler’ object in ‘Customer demand product delivery’ use-case has responsibilities to di-rect the use-case according to conditions such as required product, user’s acceptance or refusal, etc. These situations, called scenarios, are modeled in activity diagram and object model. Information model must include all attributes and operations of the object in any possible scenarios. To fulfill its responsibilities in the use-case the ‘customer handler’ object collaborates with 6 objects in the system and interacts with an actor, customer. Basically, ‘customer handler’ object has three alternatives ac-


65

cording to conditions. If customer wants standard product then it checks payment and inform delivery center to deliver the product to the customer. If customer refuses all proposals from customer handler object then customer handler object quits the use-case. These conditional flows of events are de-scribed in object model. To make the model easy to understand it is recommended that each alterna-tive be modeled in different object model respectively. In this thesis three alternatives are modeled in one object model. CRC card of ‘customer handler’ class is described in table 5 – 1. CRC card is used to identify objects from use-case description. Responsibilities in CRC card are mapped attributes and operations in in-formation model. Collaborator(s) represents classes that have relationship with the class. Consistency between these pairs must be ensured in order to obtain correct model.

Class ‘customer handler’ Responsibility Collaborator(s)

Receive application Application

Check whether customer needs standard product. Application, Standard product list

Create product specification. Product specification

Deliver product specification Product specification, GIS operator

Check payment Customer (Actor)

Create Delivery work Delivery work

Inform Delivery work Delivery work, Delivery center

Table 5-1 CRC card of ‘customer handler’ class Following diagrams are simplified model of ‘customer demand product delivery’ use-case to highlight the ‘customer handler’ object. Information model showing the attributes and operations of ‘customer handler’ object and associations between collaborators is shown in Figure 5 - 2. With this diagram it is possible to test unit object, in other words, its attributes and operations that are necessary to fulfill its responsibilities and associations through which the object interacts with others.

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Figure 5-2 ‘Customer handler’ object with related objects in information model


67

Figure 5 – 3 shows simplified object models to highlight ‘customer handler’ object for each alterna-tives. Each object model describes alternative flows of events of use-case. Consistency between in-formation model and object model, object model and use-case description must be secured. With this diagram it is possible to test integration of the models. Interactions and associations are checked in different models.

Figure 5-3 ‘Customer handler’ object in Object Model

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5.2.3.2. Answering to Assessment Questions

After completing unit and integration test on all classes and interactions, it is possible to answer to assessment questions. As mentioned earlier, the assessment result is not binary variable, in other words, ‘NO’ does not indicate the model is absolutely incorrect. It means that the assessment results must be carefully interpreted and evaluated. The evaluation of assessment question result is not ex-plained in this thesis. Assessment Questions and Results.

Assessed Result / Positive Result

Information Model Result

1 Is the class diagram drawn using UML? Y / Y

2 Do all sequence diagram objects have associated classes in the class diagram? Y / Y

3 Are design patterns used to create associations for common relationships? N / Y

4 Are there classes other than containers for which there are no corresponding ob-jects in the class diagram?

N / N

5 Are classes present not traceable to the requirements or use cases? N / N

6 Are roles identified? Y / Y

7 Are redundant classes present? N / N

8 Are multiplicities shown and correct? N / Y

Object Model Result

1 Are the sequence diagrams drawn using a consistent, preferably UML, notation? Y / Y

2 Is there a use case from which the sequence diagram derives? Y / Y

3 Is there an actor that initiates each sequence diagram the same one that initiates the use case from which it is derived?

Y / Y

4 Are all nouns, noun phrases, and verbs that imply creation represented as objects? Y / Y

5 Does the diagram have a meaningful termination? Y / Y

6 Do all of the objects present in the sequence diagram have associated classes in the class diagram?

Y / Y

7 Do the diagrams include alternatives and exceptions? Y / Y

Table 5-2 Assessment Questions to Information model and Object model

Since almost 90 % of the questions were answered positive result, this result gives the impression that the models produced in this research have sufficient accuracy. However, this evaluation is not always appropriate because of different importance of each question and different interpretation of result ac-cording to modeling purposes. It is very important that the right evaluation approach must be selected to interpret the assessment results correctly.


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5.3. Testing functional requirements of the system

Figure 5-4 Conceptual framework of functional requirements test The Figure 5 – 4 shows the conceptual framework of functional requirements test. In this test func-tional requirements of each use case from both production system and service delivery system are tested. Topographic database complying with Open GIS Specification has significant role in both sys-tems. The topographic data is stored in Oracle spatialTM database management system that complies with Open GIS Simple Feature Specification for SQL (SFS/SQL). New spatial data that are topologi-cally correct are produced by ArcInfoTM and loaded into topographic database. Data stored in Oracle spatialTM are accessed and manipulated by another GIS application in this case PCI GeomaticaTM .

5.3.1. Introduction of Oracle SpatialTM

Oracle spatialTM is the extension of Oracle 8i enterprise solution or later version. It provides spatial data management functionalities such as spatial data storage, spatial query, spatial index, and spatial operation. Spatial data in Oracle spatial are stored in table in the same way as other administrative data are stored. These tables can be queried by standard SQL statement. Oracle spatial provides full range of integration of spatial data and non-spatial data in the same database.

5.3.1.1. Object – relational DBMS

Object-Relational Database Management System (ORDBMS) combines the best of Relational Data-base Management System (RDBMS) and Object Database Management System (ODBMS). The lim-ited set of data type and operations in traditional RDBMS does not support spatial data management. Oracle spatial provides an object data type MDSYS.SDO_GEOMETRY, spatial indexing capability, and functions and operations on MDSYS.SDO_GEOMETRY object. In Oracle spatial, the spatial data and attribute data are stored in a single table. The instances of spatial data are stored in a single column in a table with attribute data.

GIS Application

Topographic Database(Oracle Spatial)

Production system Service delivery system

Create Topographicdatabase

Customer demandproducts delivery

Serv

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deliv

ery

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Prod

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ArcInfoTM PCI GeomaticaTMOracle Server and Clientapplication


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5.3.1.2. Spatial Data Model

Figure 5-5 Data Model hierarchy of Oracle spatial An element is the primitive type of a geometry such as point, linestring, and polygon. In object-relational compound linestring and compound polygon element are available. A geomety is the representation of a users’ spatial feature, modeled as an ordered set of primitive elements. A geometry can consist of a single element or a homogenous or heterogeneous collection of primitive elements. A layer is a heterogeneous collection of geometries which share the same attribute set. Layer is stored in particular column in a table. Spatial data model of Oracle spatial complies with Open GIS Simple Feature Specification for SQL (SFS/SQL).

5.3.1.3. Spatial Index

Once spatial data has been loaded into spatial tables through either bulk or transactional loading, a spatial index needs to be generated or updated for efficient access to the data. Spatial index helps speed up the execution of SQL statements in the database by providing a faster access path to data. The results of the indexing process are stored in the layer name_SDOINDEX table. Oracle spatial provides two methods for spatial indexing: quadtree indexing and R-tree indexing. • Quadtree indexing: Successive decomposition (tessellation) of a coordinate space into tiles • R-tree indexing: approximating each geometry with the smallest single rectangle that encloses the

geometry (called the minimum bounding rectangle, MBR)

5.3.1.4. Spatial Query

Spatial data stored in Oracle spatial can be accessed and manipulated by industry standard SQL statement. Figure 5 – 6 shows optimized query model. Primary filter retrieves candidate sets of data by using spatial index and then secondary filter computes to retrieve exact data.

Layer

Elements

Geometries

Polygon CompoundLineString

CompoudPolygonLineStringPoint


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Figure 5-6 Optimized Query Model Oracle spatial implements a 9-intersection model for binary topological relationships between geo-metric objects following Open GIS Specification for SFS/SQL. There are two kinds of querytype: window querytype and join querytype. Window querytype is used when finding geometric objects that fulfill given condition. Join querytype is used to find geometric object pairs that fulfill given condi-tion.

5.3.2. Create new spatial layer (table) into Topographic database

Figure 5-7 Spatial data loading into Oracle spatial database This implementation aims to test functional requirements of ‘Create topographic database’ use-case. Implementation covers last part of the use-case, that is, loading spatial data into topographic database. Topographic database is managed by Oracle enterprise server. As mentioned in section 5.3.1, Oracle spatial can manage spatial data as well as administrative data.

5.3.2.1. Spatial data for experiment

The data that are used in this experiment are topographic templates derived from 1:25,000 topog-raphic map. The data are digitized from analogue map and topologically structured in ArcInfoTM . There are many layers out of which three layers are used in this experiment (namely contour, roads, and river layers). Each layer has coverage file format and maintains topology. The area covered by the data is central part of the kingdom of Nepal. Bhaktapur—literally meaning "The City of Devotees"— is situated at an altitude of 1,401 meters (4,553 ft.) and spread over an area of 6.8 square kilometres. It is located to the east of Kathmandu, the capital city of the kingdom of Ne-pal. The map sheet covers the area between longitudes 85○22′30″ and 85○30′00″ and latitudes 27○37′30″ and 27○45′00″. The more information about the map showing the area covered by the data is given in Appendix D.

Spatial LayerPrimary Filter

Spatial Index

ReducedData set

Secondary Filter

Spatial Functions

ExactResut

Oracle spatial

SQL*LOADER

BULK LOADING

SQL*PLUS

CREATE TABLE

SQL*PLUS

TRANSACTIONAL INSERTSHP2SDO

CONVERT DATA


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5.3.2.2. Convert data

The first step of loading spatial data into database is to convert spatial data into loadable format. Loading tools are typically provided by GIS application. Shp2sdo is used in this test. It converts ShapeTM file to SQL*Loader control file which can be loaded directly. The SQL*Loader control file is a text file into which you place a description of the data to be loaded. You also use the control file to tell SQL*Loader which database tables and columns should receive the data that you are loading. After completing conversion, three files are created as follows. • Contour.ctl: SQL*Loader control file for loading the Contour.shp file. • Contour.dat: data file. • Contour.sql: creates the Contour table in database.

5.3.2.3. Create spatial table

Before loading spatial data into database, the table in which data is stored must be created. This task can be done with Oracle client software, for example, SQL*Plus. SQL*Plus is interactive user inter-face to the Oracle database management system. It provides users with command line environment to run SQL. Sql file is generated automatically when shape file is converted into SQL*Loader control file. The geometry metadata is stored in table USER_SDO_GEOM_METADATA. The geometry metadata describes the dimensions, lower and upper bounds, and tolerance in each dimension. This SQL statement creates CONT table and insert the geometry metadata into table USER_SDO_ GEOM_METADATA. For roads and river data, see appendix C. Spatial Data Loading into Oracle spa-tial.

CREATE TABLE CONT ( FNODE_ NUMBER, TNODE_ NUMBER, LPOLY_ NUMBER, RPOLY_ NUMBER, LENGTH NUMBER, CONT_ NUMBER, CONT_ID NUMBER, GEOM MDSYS.SDO_GEOMETRY); INSERT INTO USER_SDO_GEOM_METADATA (TABLE_NAME, COLUMN_NAME, DIMINFO) VALUES ('CONT', 'GEOM', MDSYS.SDO_DIM_ARRAY (MDSYS.SDO_DIM_ELEMENT('X', 635612.625000000, 642378.250000000, 0.000000050), MDSYS.SDO_DIM_ELEMENT('Y', 3057077.000000000, 3064398.000000000, 0.000000050) ) );

5.3.2.4. Load spatial data

There are two steps involved in loading spatial data into a database: loading the data into spatial ta-bles, and creating or updating the index on the spatial tables. The process of loading data can be clas-sified into two categories: • Bulk loading of data: This process is used to load large volumes of data into the database, and

uses the SQL*Loader utility to load the data. • Transactional inserts: This process is used to insert relatively small amounts of data into the data-

base, and is analogous to the insert command in SQL.


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Converted contour data is loaded by executing SQL*Loader with following command. Sqlldr userID=kwon/xxxxxxxx@geodb, control=contour.ctl, log=contour.log

After loading spatial data into a database, spatial index must be created or updated. The script for cre-ating index on geometry column in Contour table is described below.

CREATE INDEX IDX_CONTOUR ON CONTOUR (GEOM)

INDEXTYPE IS MDSYS.SPATIAL_INDEX

PARAMETERS (‘SDO_LEVEL = 6’);

SDO_LEVEL defines the fixed tile level portion of the spatial index. If spatial index is not created spa-tial query cannot be carried out. For roads and river data, see appendix C. Spatial Data Loading into Oracle spatial.

5.3.3. Produce customer demand product with data from Topographic database

In this test, it is assumed that customer needs DEM of certain area with road and river vector data. Data that are needed for customer demand product is retrieved from topographic data. In this test PCI GeomaticaTM is used as a GIS application. It provides an interface to access Oracle spatial database directly. The data is retrieved in read-only option.

Figure 5-8 Spatial data access and operation based on Oracle spatial

5.3.3.1. Data access and spatial query by SQL*Plus

Oracle spatial provides an ability to perform spatial query by SQL statement. Theoretically, we do not have to use GIS application to perform spatial analysis. For example, we can find roads running at the certain range of contour heights (between 1600m and 1800m) by using below SQL statement.

Oracle spatial

SQL*PLUS

DATA ACCESS

SQL*PLUS

SPATIALQUERY

PCIGEOMATICA

DATA ACCESS

PCIGEOMATICA

SPATIALOPERATION


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Figure 5-8 Spatial Query with standard SQL statement

Figure 5-9 The result of spatial query This SQL statement performs simple spatial query by using spatial operator MDSYS.SDO_RELATE.

5.3.3.2. Data access and spatial operation with PCI Geomatica

Spatial data stored in Oracle spatial can be accessed and retrieved by many GIS applications. The number is growing fast because it has been realized that DBMS provides GIS application with many benefits such as data security, large-scale data management, concurrent user access, and direct links to administrative data stored in the same database. PCI Gematica provides a direct connection to Oracle spatial data. The data then can be handled without conversion. In this test contour, roads, and river tables are retrieved from Oracle spatial database. A DEM is produced from contour table and roads and river table are put on the DEM. The product is shown in appendix D.


In this chapter consistency of the models and the functional requirements of the proposed system are tested. Consistency check of the models involves individual objects, integration of the objects, and the system as a whole. Unit object check is used to test consistency on object attributes and operations compared with its responsibilities and collaborators. Integration of the objects is tested by checking the interactions of the objects in object model. Interactions in object model must be able to be traced


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from associations in information model. Object from both models has consistent association and in-teraction pairs. After checking consistency on unit object and integration of objects, assessment ques-tions are answered to test the accuracy level of the models. Object-oriented modeling approach pro-vides comprehensive and understandable view of the system: external and internal model, static and dynamic model. It gives significant advantages to keep the model consistent and trace the defects from different models. When an inconsistency is found in any model, it can be traced back to the model in which the problem originated.

Testing functional requirements of the system is carried out by implementing part of the system. The purpose of this test is to verify that the system operates correctly and results in required output. In this research, test is focused on topographic database because topographic database is the key element to resolve interoperability and product diversity problem. Oracle spatialTM is selected to implement to-pographic database because it complies with Open GIS Simple Feature Specification for SQL (SFS / SQL). With the proposed topographic mapping system, it was possible that spatial data can be stored in Open GIS compliant database and the data in this database can be accessed and manipulated by a GIS application including standard SQL statement. Although few number of GIS applications are complying with Open GIS Specification at this moment it is strongly believed that in a near future the number will increase tremendously. Consequently, application of the Open GIS Specification to to-pographic database increases interoperability of spatial data within and between organizations. It en-ables production of diverse products derived from topographic database and web mapping services where customers can access, retrieve, and manipulate spatial data without conversion process.


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6. Conclusions and Recommendations

6.1. Introduction

The following sections provide conclusions of this research and recommendations for further re-search.

6.2. Conclusions

This research suggests that object-oriented modeling approach provides a number of benefits in busi-ness process modelling. It provides comprehensive and consistent modelling capability. From functional requirements of business process to its dynamic behaviour, all model development phases can be built in one modeling environment. Therefore, a model in certain development phase can be traced back to the model in previous phase. It was also found that using object concept to represent real entity minimizes the gap between the real world and its model.

The key words of this thesis are: Topographic mapping system, Open GIS Specification, Object-oriented modeling, and UML. After completing this research, following conclusions are made.

• Object-oriented modeling approach enables integrated business process management. Models of the business process include goals, workflows, various kinds of resources e.g. human resources, material resources, information resources, etc. in a consistent manner. Resources that are neces-sary to operate the business process are captured as objects. Each object is assigned responsibili-ties and collaborators in order to achieve goals of the business process. Workflow of the business process is modelled by interactions between objects, in other words, resources.

In addition Object-oriented business modelling approach, especially UML in this thesis, can be applied to from requirements gathering to behavioural modelling. Static and dynamic aspects of the business process are modelled consistently. It enables to obtain consistent model for the entire business system.

• The proposed system can improve quality management. The most important principle for quality management is user’s requirements. The users’ requirements are reflected to the system by model-ing external view of the system. The term ‘use case’ means the way in which the users use the system. Use case interacts with users to get their requirements and provide what they need. In ob-ject-oriented modeling all products from the system are modeled as objects. Required quality of the products can be identified as attributes. Quality checkers, who are also identified as objects in the model, can refer to these attributes to check quality of the products. Therefore, quality of products can be integrated with workflow and monitored throughout the workflow.

• In the proposed system architecture, there are four components including production component, service delivery component, geodatabase management component, and workflow component. These components are interacting with each other in order to play their roles in the system. In this


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system architecture, the data from various processes in the system are stored and managed in structured way to make sure that all the data must be fully exploited for internal and external use. This makes the production system more flexible. In this system there are two benefits: product di-versity and improved productivity.

The number of products available from the system increases because predefined intermediary products are stored and managed by geodatabase management component. In conjunction with new information technologies the proposed system enables to increase the overall productivity by transforming time-costing and labour-intensive tasks with efficient and effective tasks.

• The proposed system provides standard geo-spatial data by applying Open GIS compliant topog-raphic database. The Open GIS Specification is an emerging standard for geospatial data. It is widely being accepted by leading GIS enterprises. They are trying to develop new GIS application or add new functionality that complies with the Open GIS Specification. Adopting Open GIS compliant topographic database enables to provide interoperable geospatial data that can be di-rectly used by other OGIS conformant applications.

This environment where there is no problem on geospatial data sharing facilitates the develop-ment of Geo-Spatial Data Infrastructure (GSDI). The GSDI seeks to support the sharing of data in certain context, for example regional, national, or global context, by means of a set of standards. The Open GIS Specification takes care of these standards.

6.3. Recommendations

• One of the most important tasks in object-oriented modeling effort is to identify right objects and their roles and responsibilities in the business processes. It needs critical survey on the business processes and a well-organized team. However this research is not based on real business process so that it can only provide the guideline to identify the objects. Modeling based on real case study is recommended.

• UML can be used for information system modeling as well as business process modeling. Using the same type of technique for building business model and information system model makes it much easier to express the dependencies between the two (Jacobson I., 1994). In topographic mapping system there are a number of information systems that support the system. Recom-mended research in this context is to provide guideline for information system modeling from business model that defines the requirements of information system. Some approaches have been introduced by commercial industry. However, it is needed that these approaches are reviewed and modified to fit to the purpose of topographic mapping system.

• Further research on validation of object-oriented model is recommended to produce the right models for complex business process. Formalized validation approach is necessary to test the models in consistent manner; especially when the business process is very complex. Assessment Questions approach introduced in this thesis is one of alternatives. However, the selection criteria for verification of models must be clearly defined in further research. In addition performance analysis of proposed system must be taken into consideration in further research.


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• The Open GIS Specification was introduced in this research. This research is more related to Open Geodata Model. However, there are two more specifications: OpenGIS Services Model and Information Communities Model. These two models are based on Open Geodata Model and facilitate spatial data sharing. The use of these models to design Geo-Spatial Data Infrastructure (GSDI) is recommended in further research. This research can provide the basis of that research.

• In topographic mapping system, updating database and maintaining change on data are important

tasks. This research focused on creating new database so that further research on the issue of up-dating and maintaining change on the ground is recommended.


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References and bibliography

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Groot, R., 2000, Corporatisation of National Mapping Agencies: Challenges and Opportunity. Pro-ceedings of the 15th UN regional Cartographic Conference for Asia and the Pacific. Kuala Lumpur. Groot, R. & Kraak, M., 1999, Challenges and Opportunities for National Mapping Agencies Devel-opment of National Geospatial Data Infrastructure (NGDI). Proceedings of the first meeting of the Committee on Development Information (CODI) of the United Nations. Addis Ababa, Ethiopia. Groot, R. & McLaughlin, J., 2000, Geospatial Data Infrastructure; Concepts, Cases and Good Prac-tice. NY: Oxford University Press. Hammer, M. and Champy, J., 1993, Reengineering the Corporation—A Manifesto for Business Revolution. New York. NY: HarperBusiness. Harrington, H. J., 1991, Business Process Improvement: The Breakthrough Strategy for Total Qual-ity, Productivity, and Competitiveness. New York, NY: McGraw-Hill. Hawryszkiewycz, I., 1998, System Analysis and Design, fourth edition. Sydney: Prentice Hall. Hiatt, J., 1995, Winning with Quality. Addison-Wesley Longman. Greenway, I., 2002, Business Matters for Professionals: A guide to support professionals in the task of business management, Chapter 6 Managing Information and Information Technology. International Federation of Surveyors (FIG) International Organization of Standardization (ISO), ISO 9000:2000, Quality Management Prin-ciples. Jacobson, I., 1994, The Object Advantage: Business Process Reengineering with Object Technology. NY: ACM Press Legg, C., 1994, Remote Sensing and Geographic Information Systems. John Wiley & Sons Ltd. Muller, R. J., 1999, Database Design for Smarties: Using UML for Data Modeling. CA: Academic Press. Object Management Group Inc., 1999, Object Constraint Language Specification. MA: Object Management Group. Inc. Open GIS Consortium Inc., 1996, Open GIS Consortium (OGC): A Promise to Interoperability in GI. GIM, International Journal of Geomatics. Open GIS Consortium Inc., 1998, The OpenGIS Guide, Third Edition: Introduction to Interoper-able Geoprocessing and the OpenGIS Specification. Open GIS Consortium (OGC). Inc.


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Open GIS Consortium Inc., 1999, OpenGIS Simple Features Specification for OLE/COM Revision 1.1. Open GIS Consortium Inc. Open GIS Consortium Inc., 1999, OpenGIS Simple Features Specification for SQL Revision 1.1. Open GIS Consortium Inc. Paresi, C., 2001, Strategic Planning and BPR applied to GIOs. ITC Lecture Note. Prado, D., 1998, Implementation of a Service-Oriented Strategy in a Mapping Organisation. MSc Thesis. ITC Radwan, M. M. et al., 1999, Business Process Redesign and Process Modeling. ITC lecture note. Sprax Systems Pty Ltd. Enterprise Architect (EA) user guide Chapter 11. Testing support. Thomas, G., 2000, Achieving Enterprise GIS data Integration in Fairfax County using GIS everyday. Urban and Regional Information Systems Associations (URISA) 2000 annual Conference Proceed-ings. Weibel, R., 1997, Digital Terrain Modeling for Environmental Applications – A Review of Tech-niques and Future Trends. JEC/GI, Joint European Conference & Exhibition on Geographical Infor-mation. Web site: www.prosci.com (accessed on February 22, 2002) BPR Online Learning Center sponsored by ProSci. Defense of Department (DoD) in the United States. Framework for Managing Process Im-provement. Web site: www.gps.gov.uk (accessed on February 22, 2002) The National GPS Network in Ordnance Survey. Web site: www.ordsvy.gov.uk (accessed on February 22, 2002) Ordnance Survey: Britain’s National Mapping Agency Web site: www.usgs.gov/laws/index.html (accessed on February 22, 2002) Laws and Regulation Governing USGS Activities


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Appendix

Appendix A Unified Modeling Language (UML) Sources: Unified Modeling Language Specification 1.4 from Object Management Group (OMG). Business Modeling with UML: Business Patterns at work (H. Eriksson & M. Penker, 2000). OMG WWW site: http://www.omg.org/.

A - 1 Introduction Unified Modeling Language (UML) was created by Grady Booch, James Rumbaugh, and Ivar Jacob-son, and later standardized by the Object Management Group (OMG) in 1997. UML is not modeling or design methodology but a modeling language. A modeling language has a notation – the symbols used in the models – and a set of rules that govern the language. The rules are syntactic, semantic, and pragmatic. The syntactic rules dictate how the symbols should look and how they may be combined. The semantic rules tell us what each symbol means and how it should be interpreted by itself or in the context of other symbols. Pragmatic rules explain how to use the language. UML does not have prag-matic rules. In this appendix, syntactic and semantic rules of UML are explained for each diagram.

A - 2 Diagrams in UML UML has eight predefined diagrams: • Class diagram. Describes the structure of a system. The structures are built from classes and

relationships. The classes can represent and structure inforamtion, products, documents, or organizations.

• Statechart diagram. Expresses possible states of a class. • Activity diagram. Describes activities and actions taking place in a system. • Sequence diagram. Shows one or several sequences of messages sent amon a set of objects. • Collaboration diagram. Describes a complete collaboration among a set of objects. • Use-case diagram. Illustrates the relationships between use cases. Each use case, typically

defined in plain text, describes a part of the total system functionality. • Component diagram. A special case of class diagram used to describe components within a

software system. • Deployment diagram. A special case of class diagram used to describe hardware within a

software system. These diagrams capture the three important aspects of systems: structure, behavior, and functionality. According to different aspects of the system, OMG classifies diagrams into four categories. • Functionality (External view) diagram: Use-case diagram. • Static structure diagram: Class diagram. • Behavior diagram: Statechart diagram, Activity diagram, Sequence diagram, Collaboration

diagram.


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• Implementation diagram: Component diagram, Deployment diagram. In business modeling usually people use not all diagrams because some of diagrams are only necessary for software modeling. Use-case digram, Class diagram, Activity diagram, and Sequence diagram are the diagrams that are frequently used in business modeling. Following chapters explain each diagram in detail.

A - 3 Use-case diagram A use-case diagram shows the relationship among use-cases within a system or other semantic entity and their actors. Use-case diagrams show actors and use-cases together with their relationships. a use-case represents functional requirements of the system. An actor represents external environment that uses the system. An example of use-case diagram is shown in figure A – 1.

Figure A – 1 An example of Use-case diagram A - 4 Activity diagram Activity diagram is used to explore and describe a workflow , the actions performed in an operation in a class, similar to traditional program flowchart. In addition, activity diagram is used to describe business processes, workflows in the context of organization. Activity diagram as defined in the UML represent the dynamics of a system by expressing flows. They are basically flow charts that are used to show the workflow of the system. A business activity diagram provides a graphical way to document a business workflow. It provides a simple and intuitive illustration of: • What happens in a workflow, • What activities can ve done in parallel, • Whether there are alternative paths through a workflow. Activity diagram also describe the roles and areas of responsibilities in the business, in other words who is responsible for doing what in the business. Roles and areas of responsibilities are documented


Standard productdelivery

Customer demandproduct delivery

Web mapping service

Mandated client

ContractorInternet user

Customer

ActorPeople or things that use the system

System Boundary:Delineate system from external environment

Use-case:One use of the system by an actor

A functional requirement of the system


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as columns in the activity diagram. Swimlanes show which business workers participate in the realization of the workflow. Besides areas of responsibilities and specific activities, business activity diagram can also show business entities being manipulated in the activities. Business entities represent objects that are either created, updated, or used during the course of the business activity.

Things like customer profile, paycheck, order, etc.

Figure A – 2 An example of activity diagram with swimlane and object flow • Initial State: Represents the point at which a newly created object starts. • Decision: Expresses a decision when guard conditions are used to indicate different possible

transitions that are boolean dependent. • Control Flow: Represents a transition from one state to another. • Action State: Represents an activity whose purpose is to execute an action and then transition to

another state. • Transition Fork: Represents a fork transition requiring one input transition and two or more

output transitions. • Transition Join: Represents a join transition requiring two or more input transitions and one

output transition. • Swimlane: Represents a partition for organizing responsibiliy for activities.

Proposal Owner Quote OwnerCustomer Sales Interface

Initialize contact

Initial opportunity work

[Rejected]Search alternatives

[Accepted]

Create proposal profile

Finalize proposal Create a delivery project plan

Prepare a quote

Proposal(created)

Delivery project plan (created)

Quote(created)

Compile additional information

Proposal(complete)

Present the proposal

Obtain customer decision

[Change requirements]

[Rejected]

Initial State

Final State

Action State

Object in State

Transition (Join)

Transition (Fork)

Decision

Swimlane

Object Flow

Control Flow


IV

• Object Flow: Represents the flow of an object to or from an action state. • Object in State: Represents an object in particular state. • Final State: Represents the final occurance of an event at the enclosing state or the completion of

activity in the enclosing state.

A - 5 Class diagram Business class diagram documents the internal structure of the business. Each class in this diagram either represents a business worker (employee of the business) or a business entity (a ‘thing’ that the business manipulates). The purpose of business class diagram is to document the relationships between business workers and business entities. It provides a way to visualize who interacts with who and who is responsible for what. Business class diagram are used for two main purposes:

• To show business workers and business entities are collaborating to implement a business process.

• To show static structure and relationships among business entities.

Figure A – 3 An example of a class diagram

• Class: A set of object with the same characteristics. • Attribute: Represents information that an object has. • Operation: Represents a specific activity to be performed by an individual object. • Association: Represents a relationship in which one object has reference to another object • Generalization: Represents a relationship that an object of the descendant class inherits all

attributes, operations and relationships that belong to the ancestor object. • Aggregation: Represents a relationship that an object is composed of related objects

A - 6 Interaction diagram (Sequence diagram) Interaction diagram is a model that describes how groups of objects collaborate in some behavior. An interaction diagram captures the behavior of a single use-case. The diagram shows a number of objects and the messages that are passed between these objects within the use-case. Interaction

+Prepare digitalized data()+Restructure the data()+Define geometry type()+Build topology()+Edit attribute data()+Check topological integrity()+Merge and Clip adjacent area()+Validate the data()+Load data into database()+Report to project manager()

-Identity-Organizational role-Access right

«Control object»Create TopoDB::Edit operator

-Order number-Identity of operator-Work instruction-Digitalized data information

«Entity object»Create TopoDB::Work Order

Assign new work to

-Serial number-Type of data-Extent of data-Date of production-Data source-Spatial reference system-Horizontal accuracy-Vertical accuracy-File format

«Entity object»Create TopoDB::Digitalized data

Restructure +Check database integrity()+Create spatial layer()+Update spatial layer()+Delete spatial layer()+Geometric operation()+Spatial relation operation()+Spatial analysis operation()+Spatial query operation()

-Database structure-Spatial reference system-Spatial Data Model-Spatial layer structure-Constraint rule-DBMS type-Database integrity : Boolean

«Entity object»Create TopoDB::Topographic database

Load new data into

-Name-Feature geometry type-Feature Identifier structure-Attribute Information-Spatial reference system-Extent of theme-Data validity : Boolean = False-Topology : Boolean = False-File format

«Entity object»Create TopoDB::Theme

Create and edit

+Prepare project plan()+Create work order()+Assign work order()+Monitor the project()

-Organizational role

«Control object»Create TopoDB::Project manager

inform work completion


V

diagram comes in two forms based on the same underlying information, specified a collaboration and an communication. The two forms are sequence diagram and collaboration diagram. A sequence diagram shows the explicit sequence of communications and is better for real-time specifications and for complex scenarios. A collaboration diagram shows an interaction organized around the roles in the interaction and their relationships. It does not show time as a separate dimension, so the sequence of communications and the concurrent threads must be determined using sequence numbers. A sequence diagram presents an interaction, which is a set of messages between objects in the use-case. A sequence diagram has two dimensions: 1) the vertical dimension represents time and 2) the horizontal dimension represents different objects. Normally time proceeds down the page. There ia no significance to the horizontal ordering of the objects. An example of sequence diagram is shown in figure A – 4.

Figure A – 4 An example of Sequence diagram

«Interface object»Customer handler

«Entity object»Application

«Entity object»Standard product list

Get new application()

Check standard product list()Customer

Submit application()

standard product()

New product()

Make proposals()

Response to proposal()

Check payment()

Response()

Object Lifeline

Concurrent Lifeline

Message Activation


VI

• Object lifeline: Represents the existence of object at a particular time. The lifeline may split into two or more concurrent lifelines to show conditionality. Each separate track corresponds to a conditional branch in the communication. The lifeline may merge together at some subsequent point.

• Activation: Shows the period during which an object is performing an action either directly or through a subordinate procedure. It represents both the duration of the performance of the action in time and the control relationship between the activation and its callers.

• Message: Is a communication between two objects that conveys information with the expectation that action will ensue. A message cause an operation to be invoked, raise a signal, or cause an object to be created or destroyed.


VII

Appendix B Principles of verification, validation, and accredita-tion of model

Sources: O. Balci. (1998). Verification, Validation, and Accreditation. Proceedings of the 1998 Win-ter Simulation Conference. .

1 Verification & Validation must be conducted throughout the entire modeling life cycle.

2 The outcome of Verification, validation, and accreditation should not be considered as a bi-nary variable where the model or simulation is absolutely correct or absolutely incorrect.

3 A simulation model is built with respect to the Modeling & Simulation objectives and its credibility is judged with respect to those objectives.

4 Verification and validation requires independence to prevent developer’s bias.

5 Verification, validation, and accreditation is difficult and requires creativity and insight.

6 Credibility can be claimed only for the prescribed conditions for which the model or simula-tion is verified, validated and accredited.

7 Complete simulation model testing is not possible.

8 Verification, validation, and accreditation must be planned and documented.

9 Type I, II, and III errors must be prevented.

10 Errors should be detected as early as possible in the Modeling & Simulation life cycle.

11 Multiple response problems must be recognized and resolved properly.

12 Successfully testing each submodel (module) does not imply overall model credibility.

13 Double validation problem must be recognized and resolved properly.

14 Simulation model validity does not guarantee the credibility and acceptability of simulation results.

15 A well-formulated problem is essential to the acceptability and accreditation of Modeling & Simulation results.


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Appendix C Spatial Data Loading into Oracle spatial

C – 1 Roads data • Create spatial table CREATE TABLE ROADS ( FNODE_ NUMBER, TNODE_ NUMBER, LPOLY_ NUMBER, RPOLY_ NUMBER, LENGTH NUMBER, RODS_ NUMBER, RODS_ID NUMBER, GEOM MDSYS.SDO_GEOMETRY); DELETE FROM USER_SDO_GEOM_METADATA WHERE TABLE_NAME = 'ROADS' AND COLUMN_NAME = 'GEOM' ; INSERT INTO USER_SDO_GEOM_METADATA (TABLE_NAME, COLUMN_NAME, DIMINFO) VALUES ('ROADS', 'GEOM', MDSYS.SDO_DIM_ARRAY (MDSYS.SDO_DIM_ELEMENT('X', 635626.375000000, 642378.250000000, 0.000000050), MDSYS.SDO_DIM_ELEMENT('Y', 3057092.000000000, 3064398.000000000, 0.000000050) ) ); COMMIT;

• Load spatial data Sqlldr userID=kwon/xxxxxxxx@geodb, control=roads.ctl, log=roads.log

• Create Spatial Index

CREATE INDEX IDX_ROADS ON ROADS (GEOM)




IX

C – 2 River data • Create spatial table CREATE TABLE RIVER ( FNODE_ NUMBER, TNODE_ NUMBER, LPOLY_ NUMBER, RPOLY_ NUMBER, LENGTH NUMBER, RIVE_ NUMBER, RIVE_ID NUMBER, GEOM MDSYS.SDO_GEOMETRY); DELETE FROM USER_SDO_GEOM_METADATA WHERE TABLE_NAME = 'RIVER' AND COLUMN_NAME = 'GEOM' ; INSERT INTO USER_SDO_GEOM_METADATA (TABLE_NAME, COLUMN_NAME, DIMINFO) VALUES ('RIVER', 'GEOM', MDSYS.SDO_DIM_ARRAY (MDSYS.SDO_DIM_ELEMENT('X', 635634.812500000, 642378.250000000, 0.000000050), MDSYS.SDO_DIM_ELEMENT('Y', 3057083.000000000, 3064398.000000000, 0.000000050) ) ); COMMIT;

• Load spatial data Sqlldr userID=kwon/xxxxxxxx@geodb, control=river.ctl, log=river.log

• Create Spatial Index

CREATE INDEX IDX_RIVER ON RIVER (GEOM)




X

Appendix D Spatial Data for Experiment Sources: Triangulation Instruction Book, Part I Field Work. 1976. Geodetic Survey Branch, His Maj-esty’s Government of Nepal Survey Department.

D – 1 The location of the map sheet area

D – 2 Map sheet information • Map sheet number: No. 2785 06B • Publication date: 1994 • Source Data: 1: 50,000 scale aerial photography of 1992, Field verification is done in 1994. • Publisher: Survey Department of His Majesty’s Government of Nepal • Coordinate System information

o Projection System: Universal Transverse Mercator (UTM) o Spheroid: Everest Spheroid o Unit of measurement: Meter (M) o False Easting: 5000,000.00 meters o False Northing: 0 meter

• Index to sheets

2785 02C 2785 02D 2785 03C

2785 06A 2785 06B 2785 07A

2785 06C 2785 06D 2785 07C

Area of Experiment:Bhaktapur


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D – 3 Input data These data were digitized from 1: 25,000 topographic map and built geographical topology in ArcInfo coverage format. From topographic map 10 layers were derived and topologically structured. These include: Contour, District, Forest, Height (spot data), Building, Geographic Name, River, Roads, and Village Name. In this experiment, three layers were used, namely contour, river, and road layers. The coverage files were first converted into shape files because only shape file is available for bulk loading of spatial data into Oracle spatial at this moment. Three layers in coverage format used in this experiment are displayed in ArcGISTM.


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Appendix E Sample product derived from Oracle spatialTM

redesign of topographic mapping system using unified

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