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Requirements Analysis 21. 1 Moving to Design - 2005b521.ppt
© Copyright De Montfort University 2000All Rights Reserved
INFO2005Requirements Analysis
Moving to Design
Department of Information Systems
Requirements Analysis 21. 2 Moving to Design - 2005b521.ppt
© Copyright De Montfort University 2000All Rights Reserved
Learning Objectives
Examine the issues that have to be addressed during design
Distinguish between System and Object Design
Consider the impact of implementation technology
UP, Design and Implementation
Requirements Analysis 21. 3 Moving to Design - 2005b521.ppt
© Copyright De Montfort University 2000All Rights Reserved
Analysis vs Design
Why separate analysis and design Project Management, Staff Skills and Experience, Client Decisions Choice of Development Environment.
Requirements Analysis 21. 4 Moving to Design - 2005b521.ppt
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What makes a good analysis To provide a sound foundation for
design, analysis should meet the following four criteria:
Requirements Analysis 21. 5 Moving to Design - 2005b521.ppt
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What makes a good design
Requirements Analysis 21. 6 Moving to Design - 2005b521.ppt
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What makes a good design
Requirements Analysis 21. 7 Moving to Design - 2005b521.ppt
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Measurable Objectives
Information systems are built to satisfy an organisational need such as
Measurable objectives might include
However not all objectives are quantifiable
Requirements Analysis 21. 8 Moving to Design - 2005b521.ppt
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Logical vs Physical Design
One way of separating design by splitting it into – Logical design – Physical design
Requirements Analysis 21. 9 Moving to Design - 2005b521.ppt
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Logical vs Physical Design
Physical design is affected by
Requirements Analysis 21. 10 Moving to Design - 2005b521.ppt
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Logical vs Physical Design
Logical design is concerned – how objects interact determining
Requirements Analysis 21. 11 Moving to Design - 2005b521.ppt
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Logical vs Physical Design
One logical design leads to various physical designs (and implementations).
Distinction made much less these days
System architecture enables different styles of implementation
Requirements Analysis 21. 12 Moving to Design - 2005b521.ppt
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System and Object Design
System Design is concerned with
Object Design is
Requirements Analysis 21. 13 Moving to Design - 2005b521.ppt
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System Design
Sub-systems and major components are identified.
Any inherent concurrency is identified.
Sub-systems are allocated to processors.
Requirements Analysis 21. 14 Moving to Design - 2005b521.ppt
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System Design
A data management strategy is selected.
A strategy and standards for human-computer interaction are chosen.
Code development standards are specified.
Requirements Analysis 21. 15 Moving to Design - 2005b521.ppt
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System Design
The control aspects of the application are planned.
Test plans are produced. Priorities are set for design trade-offs. Implementation requirements are
identified (for example, data conversion).
Architectural patterns may be used.
Requirements Analysis 21. 16 Moving to Design - 2005b521.ppt
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System Design
Campaign Database
Campaign Domain
Advert Sub-system
Advert HCI Sub-system
Campaign Costs Sub-system
Campaign Costs HCI Sub-system
A single domain layer supports two application sub-systems.
Application layer
Presentation layer
A typical software architecture
Bennett, McRobb, Farmer, 1999
Requirements Analysis 21. 17 Moving to Design - 2005b521.ppt
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User Interface Package
Business Objects Package
JDBC
Java SQL
Java AWT Application Windows
Database Package Business Objects
Control Objects
Object to Relational
UML packages representing layers in the three-tier architecture
Bennett, McRobb, Farmer, 1999
Requirements Analysis 21. 18 Moving to Design - 2005b521.ppt
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Detailed or Object Design
This involves making decisions regarding
Requirements Analysis 21. 19 Moving to Design - 2005b521.ppt
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Object Design
BankAccount
-nextAccountNumber:Integer -accountNumber:Integer -accountName:String {not null} -balance:Money = 0 -overdraftLimit:Money
+open(accountName:String):Boolean +close():Boolean +credit(amount:Money):Boolean +debit(amount:Money):Boolean +viewBalance():Money #getBalance():Money -setBalance(newBalance:Money) #getAccountName():String #setAccountName(newName:String)
Bennett,McRobb,Farmer, 1999
Requirements Analysis 21. 20 Moving to Design - 2005b521.ppt
© Copyright De Montfort University 2000All Rights Reserved
RUP Phases
Inception– business case– plan
Elaboration– use cases– baseline architecture
Construction– product is built
Transition– beta release/testing/training
Rational Unified Process
Requirements Analysis 21. 21 Moving to Design - 2005b521.ppt
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The Rational Unified Process
Rational Unified Process
Requirements Analysis 21. 22 Moving to Design - 2005b521.ppt
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The Analysis & Design Workflow
Rational Unified Process 2000
Requirements Analysis 21. 23 Moving to Design - 2005b521.ppt
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Design Activities
Centred around the software architecture
Production of the Design Model
Requirements Analysis 21. 24 Moving to Design - 2005b521.ppt
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Implementation & UP
The purpose of implementation is: – to define the organization of the code, in terms of
implementation subsystems organized in layers, – to implement classes and objects in terms of
components (source files, binaries, executables, and others),
– to test the developed components as units, and – to integrate the results produced by individual
implementers (or teams), into an executable system.
Requirements Analysis 21. 25 Moving to Design - 2005b521.ppt
© Copyright De Montfort University 2000All Rights Reserved
Summary
Examine the issues that have to be addressed during design
Distinguish between System and Object Design
Consider the impact of implementation technology
UP, Design and Implementation
Requirements Analysis 21. 26 Moving to Design - 2005b521.ppt
© Copyright De Montfort University 2000All Rights Reserved
References Bennett, S. et. al. “Object-Oriented
Systems Analysis & Design using UML” McGraw-Hill 2002
Jacobson, I., Booch, G. & Rumbaugh, J. (1999) “The Unified Software Development Process” Addison-Wesley
Rational Unified Process Best Practices for Software Development Teams White Paper, 1998 www.rational.com
Rational Unified Process 2000
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