Kollaborative Klassroom Template

Business Information Systems
Application Development III

The Unified Process

Prithwis Mukerjee, Ph.D.

Incremental Model

Non-incremental, e.g. Waterfall, rapid prototyping models

Operational quality complete product at end

Incremental model

Operational quality portion of product within weeks

Each release adds more functionality, i.e., a new increment

DesignCodingTestDeploymentDesignCodingTestDeploymentDesignCodingTestDeploymentRequirements

Release 1Release 2Release 3

Evolutionary Model

Advantages

Constant customer involvement and validation

Allows for good risk management

Disadvantages

Build-and-fix danger

Contradiction in terms

New versions implement new and evolving requirements

DesignCodingTestDeploymentRequirementsDesignCodingTestDeploymentRequirementsDesignCodingTestDeploymentRequirements

FeedbackVersion 1Version 1Version 1

Spiral model

Radial dimension: cumulative cost to date

Angular dimension: progress through the spiral

If all risks cannot be resolved, the project is immediately terminated

What is a process ?

A series of steps that specify the way

Clients

Analysts

Designers

Programmers

Would work together to create a new system

A process defines Who is doing What, When and How to reach a certain goal.

In software engineering the goal is to build a software product or to enhance an existing one

Various Processes exist

SDLC Process / Waterfall Method

Unified Process / Unified Modeling Language

The Unified Process

Unified Process (UP) is a methodology proposed by three amigos: Booch, Jacobson, Rumbaugh

They are also the co-developers of the Unified Modeling Language (UML). They formed a company called Rational which was bought over by IBM

Non Commercial and Free piece of knowledge

Rational Unified Process

The proprietory process, based on the Unified Process, along with a suite of tools that allow one to use the process effectively

Commercial Product

What is UML

Is a language.

It is not simply a notation for drawing diagrams, but a complete language for capturing knowledge(semantics) about a subject and expressing knowledge(syntax) regarding the subject for the purpose of communication.

Applies to modeling and systems.

Modeling involves a focus on understanding a subject (system) and capturing and being able to communicated in this knowledge.

It is the result of unifying the information systems and technology industrys best engineering practices (principals, techniques, methods and tools).

UML Consists of a set of Artefacts

Unified Process : 4 Phases

Inception

Business case

Scope

Vague estimates

Continue or stop?

Elaboration

Identification of most requirements

Iterative implementation of the core architecture

resolution of high risks

InceptionElaborationConstructionTransition

timeConstruction

Iterative implementation of lower risk elements

Preparation for deployment

Transition

Beta tests

Deployment

Iterative and Incremental Development

development is organized into a series of iterations

short fixed-length mini-projects (2 to 6 weeks)

timeboxed (i.e. fixed length iterations)

shift tasks to future iterations if necessary ...

an iteration represents a complete development cycle

incl. requirements,

the outcome of each iteration:
a tested, integrated and executable system

PreliminaryIteration

Iter. #1Iter. #2

InceptionElaborationConstructionTransition

Milestone

Release

Final productionrelease

1. Inception Phase

Obtain buy-in from all interested parties

Capture initial requirements

Analyse Cost and Benefits

Analyse Initial Risks

Define Scope of Project

Define candidate architecture

Language ? RDBMS ? Tiers ?

Develop a disposable prototype

Look and Feel of the application

2. Elaboration Phase

Define System Requirements

Develop USE CASE MODELS

Actors

USE CASE

Scenarios

Use Case Diagrams

Use Case Descriptions

Develop Class diagrams

Define Glossary of terms

Refine Risk Assesment

Revised Architecture Document

3. Construction Phase

From paper documents to computer programs

Cumulative increase in functionality

Increasing depth of implementation

Stubs fleshed out

Implementation of bells and whistles

Increasing severity of testing

More and more complex test cases

implement all details, not only those of central architectural value

Analysis continues, but design and coding predominate

4. Transition Phase

Transfer of the system to the user community

Includes manufacturing, shipping, installation, training, technical support and maintenance

Development team begins to shrink

Control is moved to maintenance team

Alpha, Beta, and final releases

Software updates

Integration with existing systems (legacy, existing versions, etc.)

Unified Process Disciplines

ManagementEnvironmentBusiness ModelingImplementationTestDesignPreliminary
Iteration(s) Iter.
#1

PhasesProcess DisciplinesIterations

Iter.
#2 Iter.
#n Iter.
#n+1 Iter.
#n+2 Iter.
#m Iter.
#m+1Deployment

Configuration MgmtRequirements

ElaborationTransitionInceptionConstruction

Supporting Disciplines

Use Case Model : Actors

Actors will interact with the system

Input Information

Request Information

Who could be

Distinct individuals

Same individual with multiple roles

Other computer systems

Product Manager

Salesman

ProductionPlanning System

FinancialSystem

Use Case Models

Define the tasks that the Actors will pursue

for example

Define a Product

Define a new Customer

Create an Order

List of all Outstanding Orders

List of all fulfilled Orders

Create USE CASE diagram

UML syntax

Stick figures - actors

Ovals use cases

System boundary

No control on anything outside the system

Product Manager

Salesman

Define Customer

Define Product

Create Order

DisplayOutstandingOrders

Update Order

Use Case Diagrams

Use Case Diagrams describe the functionality of a system and users of the system. These diagrams contain the following elements:

Actors, which represent users of a system, including human users and other systems.

Use Cases, which represent functionality or services provided by a system to users.

Scenarios

A USE CASE could consist of a number of scenarios

A USE CASE specifies a goal

Create ORDER, Create Customer

A SCENARIO represents a particular outcome when attempting to reach the goal.

Create Order

Old customer, good credit rating

New customer, no credit rating

Old customer, bad credit rating

The action to be followed in each case will be different

In a formal development process, each scenario would have its own documentation describing in detail all the events in the scenario

Use Case Descriptions

Detailed Description of what the USE CASE means

The USE CASE diagram gives the big picture but does not provide detailed description of what is happening

Various formats are possible

Paragraph of text

Two Column approach

First column : Actor action

Second column : System action

More complexity

Pre-condition

Post-condition

Sequence of steps

Activity Diagram or Flowchart

Sequence Diagram

Activity Diagram

DisplayOrder EntryScreenDoesCustomer exist ?Order valuewithincredit ?

Define Customer

Add Order RecordDisplayError Message

NO

NO

From Use Cases to Classes

Nouns in the Use Cases are candidates for

Classes

Order, Customer

Attributes

Order number, customer id

Verbs in the Use Cases are candidates for

Methods

Identification of Classes, Attributes, Methods is an iterative process

Class Diagram is the connection between

Object Oriented Programming techniques of the Unified Process and

Data Modelling techniques that result in Entities and Attributes in Third Normal form

Class Diagrams

ORDER

CUSTOMER

ORDER ITEM

PRODUCT

N1Receive, Update, Bill

Create, Deliver

Create, Update, CreditCheck, ...

Create, SetPrice

N1

N1

Mandatory, Must Have

Optional, May Have

Class Diagrams

Class Diagrams describe the static structure of a system, or how it is structured rather than how it behaves. These diagrams contain the following elements.

Classes, which represent entities with common characteristics or features. These features include attributes, operations and associations.

Associations, which represent relationships that relate two or more other classes where the relationships have common characteristics or features. These attributes and operations.

Sequence Diagram

Salesman

:MainScreen

: OrderEntry Screen

: OrderItem Screen

Order

Order-Item

New

New

Get Data

New

: OrderItem Screen

New

Get Data

New

X

New

Start

Challenge

ID/PW

X

Sequence Diagrams

Sequence Diagrams describe interactions among classes. These diagrams focus on classes and the messages they exchange to accomplish some desired behavior. Sequence diagrams contain the following elements:

Class roles, which represent roles that objects may play within the interaction.

Lifelines, which represent the existence of an object over a period of time.

Activations, which represent the time during which an object is performing an operation.

Messages, which represent communication between objects.

UML Diagrams Are Key System Artifacts

Actor A

Use Case 1

Use Case 2

Actor B

Document

FileManager

GraphicFile

File

Repository

DocumentList

FileList

Customer

nameaddrwithdraw()fetch()send()receive()

Forward Engineering(Code Generation)and Reverse Engineering

Executable System

User InterfaceDefinitionDomain Expert

Use Case 3

Source Code edit, compile, debug, link

Use-Case DiagramClass DiagramCollaboration DiagramSequence DiagramComponent
DiagramState DiagramPackage
DiagramDeployment
DiagramClassThe UML provides a single, common modeling language that is useable across many methods, across the entire lifecycle, and across many different implementation technologies. It maps the artifacts between business engineering, requirements capture and analysis, design, implementation, and test. It defines an expressive and consistent notation that can point out omissions and inconsistencies. It scales to support very small to very large systems development. If facilitates effective communications with all members of the development team.

We are beginning the transition from the UML to the RUP. The students are not expected to be able to read this slide. The point is just to summarize all of the UML diagrams used for visual modeling. You might point out that learning the UML and all of its diagrams is not enough for a developer to be successful. It is similar to learning a natural language like English by reading the dictionary. You might know all the words and even the syntax, but you wouldnt be able to effectively communicate. So the UML is a crucial first step as it gives us a common language with which to communicate. But a process is needed to understand how to apply the UML to ensure successful development efforts. Thats why we developed the RUP. Activity diagrams are not shown on the slide. Activity diagrams can be used to model workflows in business process engineering.

Benefits of a Use-Case Driven Process

Use cases are concise, simple, and understandable by a wide range of stakeholders

End users, developers and acquirers understand functional requirements of the system

Use cases drive numerous activities in the process:

Creation and validation of the design model

Definition of test cases and procedures of the test model

Planning of iterations

Creation of user documentation

System deployment

Use cases help synchronize the content of different models

The important point to get across is that use cases permeate all parts of RUP and are a key mechanism in accomplishing the Managing Requirements best practice.

Summary: Unified Process

The Unified Modeling Language (UML) is a language for specifying, visualizing, constructing, and documenting the artifacts of a software-intensive system

A software development process defines Who is doing What, When and How in building a software product

The Rational Unified Process has four phases: Inception, Elaboration, Construction and Transition

Each phase ends at a major milestone and contains one or more iterations

An iteration is a distinct sequence of activities with an established plan and evaluation criteria, resulting in an executable release

Rational Unified Process is a commercial version of this methodology developed by IBM / Rational

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Prithwis Mukerjee

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Eighth Outline Level

Ninth Outline Level

Order ID

Item ID

Product ID

Item quantity

Item Deliver Date

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Product Desc

Product unit price

???Page ??? (???)02/02/2008, 11:34:44Page / Customer ID

Customer Name

Customer Address

Customer Credit Limit

???Page ??? (???)02/02/2008, 11:43:51Page / Order ID

Order Date

Customer ID

Order Value

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