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PowerPoint Presentation for Dennis, Wixom & Tegardem Systems Analysis and Design
Copyright 2001 © John Wiley & Sons, Inc. All rights reserved.Slide 1
INTRODUCTION
Chapter 1
PowerPoint Presentation for Dennis, Wixom & Tegardem Systems Analysis and Design
Copyright 2001 © John Wiley & Sons, Inc. All rights reserved.Slide 2
Key Ideas
Many failed systems were abandoned because analysts tried to build wonderful systems without understanding the organization.The primarily goal is to create value for the organization.
PowerPoint Presentation for Dennis, Wixom & Tegardem Systems Analysis and Design
Copyright 2001 © John Wiley & Sons, Inc. All rights reserved.Slide 3
Key Ideas
The systems analyst is a key person analyzing the business, identifying opportunities for improvement, and designing information systems to implement these ideas.It is important to understand and develop through practice the skills needed to successfully design and implement new information systems.
PowerPoint Presentation for Dennis, Wixom & Tegardem Systems Analysis and Design
Copyright 2001 © John Wiley & Sons, Inc. All rights reserved.Slide 4
THE SYSTEMS DEVELOPMENT LIFE CYCLE
PowerPoint Presentation for Dennis, Wixom & Tegardem Systems Analysis and Design
Copyright 2001 © John Wiley & Sons, Inc. All rights reserved.Slide 5
Major Attributes of the Lifecycle
The projectMoves systematically through phases where each phase has a standard set of outputsProduces project deliverablesUses deliverables in implementationResults in actual information systemUses gradual refinement
PowerPoint Presentation for Dennis, Wixom & Tegardem Systems Analysis and Design
Copyright 2001 © John Wiley & Sons, Inc. All rights reserved.Slide 6
Project Phases
PlanningWhy build the system?
AnalysisWho, what, when, where will the system be?
DesignHow will the system work?
ImplementationSystem delivery
PowerPoint Presentation for Dennis, Wixom & Tegardem Systems Analysis and Design
Copyright 2001 © John Wiley & Sons, Inc. All rights reserved.Slide 7
A “Simple” Process for Making Lunch
PowerPoint Presentation for Dennis, Wixom & Tegardem Systems Analysis and Design
Copyright 2001 © John Wiley & Sons, Inc. All rights reserved.Slide 8
Identifying business valueAnalyze feasibilityDevelop work planStaff the projectControl and direct project
Planning
PowerPoint Presentation for Dennis, Wixom & Tegardem Systems Analysis and Design
Copyright 2001 © John Wiley & Sons, Inc. All rights reserved.Slide 9
AnalysisInformation gatheringProcess modelingData modeling
Analysis
PowerPoint Presentation for Dennis, Wixom & Tegardem Systems Analysis and Design
Copyright 2001 © John Wiley & Sons, Inc. All rights reserved.Slide 10
Physical designArchitectural designInterface designDatabase and file designProgram design
Design
PowerPoint Presentation for Dennis, Wixom & Tegardem Systems Analysis and Design
Copyright 2001 © John Wiley & Sons, Inc. All rights reserved.Slide 11
ConstructionInstallation
Implementation
PowerPoint Presentation for Dennis, Wixom & Tegardem Systems Analysis and Design
Copyright 2001 © John Wiley & Sons, Inc. All rights reserved.Slide 12
Processes and Deliverables
Process Product
Planning
Analysis
Design
Implementation
Project Plan
System Proposal
System Specification
New System and Maintenance
Plan
PowerPoint Presentation for Dennis, Wixom & Tegardem Systems Analysis and Design
Copyright 2001 © John Wiley & Sons, Inc. All rights reserved.Slide 13
THE EVOLUTION OF SYSTEM DEVELOPMENT
PowerPoint Presentation for Dennis, Wixom & Tegardem Systems Analysis and Design
Copyright 2001 © John Wiley & Sons, Inc. All rights reserved.Slide 14
What Is a Methodology?
A formalized approach or series of stepsWriting code without a well-thought-out system request may work for small programs, but rarely works for large ones.
PowerPoint Presentation for Dennis, Wixom & Tegardem Systems Analysis and Design
Copyright 2001 © John Wiley & Sons, Inc. All rights reserved.Slide 15
Structured Design
Projects move methodically from one to the next stepGenerally, a step is finished before the next one begins
PowerPoint Presentation for Dennis, Wixom & Tegardem Systems Analysis and Design
Copyright 2001 © John Wiley & Sons, Inc. All rights reserved.Slide 16
Waterfall Development Method
PowerPoint Presentation for Dennis, Wixom & Tegardem Systems Analysis and Design
Copyright 2001 © John Wiley & Sons, Inc. All rights reserved.Slide 17
Pros and Cons of the Waterfall Method
Pros Cons
Identifies systems requirements long before programming begins
Design must be specified on paper before programming begins
Long time between system proposal and delivery of new system
PowerPoint Presentation for Dennis, Wixom & Tegardem Systems Analysis and Design
Copyright 2001 © John Wiley & Sons, Inc. All rights reserved.Slide 18
Alternatives to the SDLC
Rapid Application Development (RAD)Phased DevelopmentPrototypingThrow-Away Prototyping
PowerPoint Presentation for Dennis, Wixom & Tegardem Systems Analysis and Design
Copyright 2001 © John Wiley & Sons, Inc. All rights reserved.Slide 19
Rapid Application Development
Critical elementsCASE toolsJAD sessionsFourth generation/visualization programming languagesCode generators
PowerPoint Presentation for Dennis, Wixom & Tegardem Systems Analysis and Design
Copyright 2001 © John Wiley & Sons, Inc. All rights reserved.Slide 20
Rapid Application Development Categories
Phased developmentA series of versions
PrototypingSystem prototyping
Throw-away prototypingDesign prototyping
PowerPoint Presentation for Dennis, Wixom & Tegardem Systems Analysis and Design
Copyright 2001 © John Wiley & Sons, Inc. All rights reserved.Slide 21
How Prototyping Works
PowerPoint Presentation for Dennis, Wixom & Tegardem Systems Analysis and Design
Copyright 2001 © John Wiley & Sons, Inc. All rights reserved.Slide 22
Throwaway Prototyping
PowerPoint Presentation for Dennis, Wixom & Tegardem Systems Analysis and Design
Copyright 2001 © John Wiley & Sons, Inc. All rights reserved.Slide 23
Object-Oriented Analysis and Design
Attempts to balance emphasis on data and processUses Unified Modeling Language (UML) for diagramming
Use-case DrivenArchitecture CentricIterative and Incremental
PowerPoint Presentation for Dennis, Wixom & Tegardem Systems Analysis and Design
Copyright 2001 © John Wiley & Sons, Inc. All rights reserved.Slide 24
BASIC CHARACTERISTICS OF OBJECT-ORIENTED SYSTEMS
PowerPoint Presentation for Dennis, Wixom & Tegardem Systems Analysis and Design
Copyright 2001 © John Wiley & Sons, Inc. All rights reserved.Slide 25
Key Elements
Classes -- template to define objects
Instances -- specific examples of class members
Objects -- building block of the system
Attributes -- describe data aspects of the object
Methods -- the processes the object can perform
Messages -- instructions sent to or received from other objects
PowerPoint Presentation for Dennis, Wixom & Tegardem Systems Analysis and Design
Copyright 2001 © John Wiley & Sons, Inc. All rights reserved.Slide 26
A Class and Its Objects
PATIENT
-Name-Birthdate-Phone Number+Insert ()()+Delete ()()
PATIENT 1: TOP PACKAGE: PATIENT
-Name = Teresa Marks-Birthdate = March 16, 1975-Phone number = 314-997-3456
PATIENT 2: TOP PACKAGE: PATIENT
-Name = Mel Bourne-Birthdate = May 11, 1965-Phone number = 314-997-3219
Attributes
Methods
Class
Instantiated Objects of the Class
PowerPoint Presentation for Dennis, Wixom & Tegardem Systems Analysis and Design
Copyright 2001 © John Wiley & Sons, Inc. All rights reserved.Slide 27
The Key to Reusability
Information hiding is the principle that only information required to use the object is available outside the objectEncapsulation is the mechanism that combines data and processes in a single object
PowerPoint Presentation for Dennis, Wixom & Tegardem Systems Analysis and Design
Copyright 2001 © John Wiley & Sons, Inc. All rights reserved.Slide 28
Class Hierarchy
PowerPoint Presentation for Dennis, Wixom & Tegardem Systems Analysis and Design
Copyright 2001 © John Wiley & Sons, Inc. All rights reserved.Slide 29
Inheritance
PowerPoint Presentation for Dennis, Wixom & Tegardem Systems Analysis and Design
Copyright 2001 © John Wiley & Sons, Inc. All rights reserved.Slide 30
Polymorphism
PowerPoint Presentation for Dennis, Wixom & Tegardem Systems Analysis and Design
Copyright 2001 © John Wiley & Sons, Inc. All rights reserved.Slide 31
OBJECT-ORIENTED ANALYSIS AND DESIGN USING UML
PowerPoint Presentation for Dennis, Wixom & Tegardem Systems Analysis and Design
Copyright 2001 © John Wiley & Sons, Inc. All rights reserved.Slide 32
UML
The full UML provides 9 separate diagramming techniques
PowerPoint Presentation for Dennis, Wixom & Tegardem Systems Analysis and Design
Copyright 2001 © John Wiley & Sons, Inc. All rights reserved.Slide 33
PROJECT TEAM ROLES AND SKILLS
PowerPoint Presentation for Dennis, Wixom & Tegardem Systems Analysis and Design
Copyright 2001 © John Wiley & Sons, Inc. All rights reserved.Slide 34
Information Systems Roles
Business analystSystem analystInfrastructure analystChange management analystProject manager
PowerPoint Presentation for Dennis, Wixom & Tegardem Systems Analysis and Design
Copyright 2001 © John Wiley & Sons, Inc. All rights reserved.Slide 35
Summary -- Part 1
The Systems Development Lifecycle consists of four stages: Planning, Analysis, Design, and Implementation
There are three major development methodologies: the waterfall method, RAD, and the Object-Oriented approach.
PowerPoint Presentation for Dennis, Wixom & Tegardem Systems Analysis and Design
Copyright 2001 © John Wiley & Sons, Inc. All rights reserved.Slide 36
Summary -- Part 2
There are six major elements in Object-Oriented design: classes, objects, instances, attributes, methods, and messages.Encapsulation, Inheritance, and Polymorphism are also important object-oriented conceptsThere are five major team roles: business analyst, systems analyst, infrastructure analyst, change management analyst and project manager.
PowerPoint Presentation for Dennis, Wixom & Tegardem Systems Analysis and Design
Copyright 2001 © John Wiley & Sons, Inc. All rights reserved.Slide 37
Expanding the Domain
For complete description of UML see:www.rational.com/uml