Enterprise Information Systems Architecture (ISA)Modeling Roadmap

Definitions

ISA domains & levels

ISA analysis techniques

Review questions

Definition 0: Information Systems Architecture in Enterprise Architecture

• ISA partly stems from and partly overlaps with Business Architecture

• The main contact point are Business Processes (BP)

• Indeed most requirements for ISA come from BP, e.g. what transactions and reports the information systems should process

• Therefore most requirements analysis techniques cover both BP and information analysis

2

Definition 1 : User Requirements (UR)

• ISA is based on User Requirements (UR) • UR reflect the needs of the users on three main

domains, namely • the interface of the users with a computer system

• the information the users handle

• the logic / rules and the flow of activities the users perform

• UR are a higher abstraction level of systems / processing requirements that are usually described by UML

Definition 3: User Needs (UN)

• “User Needs” (UN) are what users should get from a system• “User requirements” (UR) describe what the system should do

(hopefully consistently with needs) regardless its implementation

• There are some critical points in UN– Seldom users know what they want and even less frequently know

how to represent it in a useful form for software development – Therefore :

• Needs should be elicited i.e. the user should be guided to express his/her own view of needs

• Requirements should be obtained by transforming and/ or mapping of the user’s view in a systems analysis view

• Requirements should be compared against a best practice or reference model

• We call this approach «Functional analysis»

Definition 4: Functional Analysis (FA)

• Analysis: – Identification of the structure of an object or of a statement through the

decomposition of an object in smaller parts according to a predefined rule = structure

– Origin of term: it dates back to the “Analytica Priora”, where Aristotle introduces syllogistic method, argues for correctness, and discusses inductive inference.

• Information system: a system of functions that collect, process, store and distribute information

• Function: – An activity with an outcome – Example in Information Systems: “read”

• Functional analysis of information systems: – Scope: defines the functions of an information system according to a given

model – Purpose: defines what the system should do (i.e. the functions) regardless

the implementation technology

Definition 2 : Requirements analysis (Wikipedia 2012)

• In systems engineering and software engineering, encompasses those tasks that go into determining the needs or conditions to meet for a new or altered product, taking account of the possibly conflicting requirements of the various stakeholders, such as beneficiaries or users.

• It is an early stage in the more general activity of requirements engineering which encompasses all activities concerned with eliciting, analyzing, documenting, validating and managing software or system requirements.

• Requirements analysis is critical to the success of a systems or software project.

• Requirements should be documented, actionable, measurable, testable, traceable, related to identified business needs or opportunities, and defined to a level of detail sufficient for system design.

Enterprise Information Systems Architecture (ISA)Modeling Roadmap

Definitions

ISA domains & levels

ISA analysis techniques

Review questions

ISA modelling levels

Layer Target Notations Explanation

ASLAggregate StrategicLayer

Aggregate needs

List / Grid Needs are aggregate and expressed by simple notations, as grids or lists

RSLRich Semantic Layer

Detailed needs

Diagrams Specification languages

Needs are detailed and expressed by diagramsRSL is conceptual and neglects the implementation of requirements

SEI Software Engineering Interface

Software Diagrams Specification & programming languages

Transforms RSL into a notation targeting software engineersIn most cases such notation is executable.

ISA modelling domains

Domain Explanation Information Describes the structure and properties of the

information the system shall use (database) Process (workflow) Describes the workflow of the business

processes and related execution rulesUser interface Describes the user interface, through which

information is distributed to (or collected from) users.

The analysis should cover the aspects of the system the users perceive, that we term as “domains”.

ISA modelling grid

Analysis Layer

Analysis Domain

Information Business functions User Interface

ASL Business Information Models

Business models (e.g. financial mathematical models; KPI) Stakeholder / Goal

Oriented Conceptual Models

ESL Conceptual Information Models

UML & BPMN (flow intensive systems)

SEI Implementation Frameworks / Platforms

Implementation Frameworks / Platforms

GUI Implementation Frameworks/ Platforms

Enterprise Information Systems Architecture (ISA)Modeling Roadmap

Definitions

ISA domains & levels

ISA analysis techniques

Review questions

ASL / information: SIRE

• SIRE (Strategic Information Requirements Elicitation) is a catalog of the information domains of an enterprise.

• It uses a grid model, where information domains are layered into information levels, namely 1. master information

2. event information

3. analytic information

• Developed in University of Pavia (2008)

Information Domain

Information Level

Master Event Analysis

Domain 1      

……      

Domain n      

Analysis Layer

Analysis DomainInformation Process User

Interface ASLRSMSEI

ASL / Process: GEF

• GEF (General Enterprise Framework) lists the activities of business processes (BP) at the respective layers: 1. Planning (e.g. Sales Planning)2. Execution (Proposal and

Selling tasks)3. Monitoring to check execution

workflow (where is the order of Mr. Smith?)

4. Control to appraise actual results (are we on budget?)

5. Information, to manage information collection, storage and distribution

• Developed in University of Pavia (2012)

Analysis Layer

Analysis DomainInformation Process User

Interface ASLRSMSEI

Layer Business Process Process 1 Process

…Process N

Planning      Execution      Monitoring      Control      Information      

RSM / Information: ER & DFM

• ER (Entity Relationship) – Models information at a

conceptual level

– Not for analytic information

– Developed by Chen (1976)

• DFM (Dimensional Fact Model) – Models analytic information by

a specific notation.

– It is a conceptual technique

– Developed in University of Bologna (1998)

Analysis Layer

Analysis DomainInformation Process User

Interface ASLRSMSEI

RSM / Process: BPM & UML

• BPMN (Business Process Management Notation)– Models the flow of business

processes. – Typically a BPMN flow details a

GEF quadrant.

• UML-EP (Unified Modeling Language with the Erikson Penker estension) – It is a business oriented

extension of UML, – It adds models to represent the

flow of a Business Process – It supports the elicitation of Use

Cases and Candidate Database Entities

Analysis Layer

Analysis DomainInformation Process User

Interface ASLRSMSEI

RSM / User Interface : GOA

Analysis Layer

Analysis DomainInformation Process User

Interface ASLRSMSEI

• GOA (Goal Oriented Analysis) – The analyst identifies the

goals of each user class and the actions implied on the system

– Actions are candidate use cases

– It is a conceptual technique

– Developed in Politecnico di Milano (2004)

SEI level Analysis

Layer Analysis Domain

Information Process User Interface

ASLRSMSEI

• SEI (Software Engineering Interface) is the final transformation stage, into which conceptual notations are transformed into executable languages.

• Various modeling techniques – BPEL (Business Process

Executive Language) for workflow implementation

– UML (Unified Modeling Language) for object oriented development (Class Diagrams & Use Cases)

– Relational model for databases and data warehouses

Commerciale

Direttore Produzione

Calcola FabbisogniLordi

Calcolo CapacitàNecessaria Buy

Calcolo CapacitàNecessaria Make

Carica Previsioni

Conferma QuoteOrdinate

Imposta Previsioni

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Enterprise Information Systems Architecture (ISA)Modeling Roadmap

Definitions

ISA domains & levels

ISA analysis techniques

Review questions

Review questions

• Preliminary definitions – May an individual i belong to different classes A, B, C ? In which

case yes and in which not?– Consider a simple class e.g. a Volkswagen Golf

• What is an individual of Volkswagen Golf class?• What is a specialization of Volkswagen Golf?• Is Volkswagen Golf an aggregation of Engine, Car-body etc.?

– Describe the overall model taxonomy– Describe constructions types and interpretation of Model M*– Could you define a Model richer then M?

• Modeling grid – Which are the differences between User Needs and User

Requirements?– Define Levels and Domains of Functional Analysis in terms of

• Objectives • Modeling Level