OOD_ch01.ppt

PowerPoint Presentation for Dennis, Wixom & Tegardem Systems Analysis and Design
Copyright 2001 © John Wiley & Sons, Inc. All rights reserved.
Slide 1
INTRODUCTION
Chapter 1

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.

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.

Slide 4
THE SYSTEMS
DEVELOPMENT LIFE
CYCLE

Slide 5
Major Attributes of the
Lifecycle
The project
Moves systematically through phases
where each phase has a standard set
of outputs
Produces project deliverables
Uses deliverables in implementation
Results in actual information system
Uses gradual refinement

Slide 6
Project Phases
Planning
Why build the system?
Analysis
Who, what, when, where will the system be?
Design
How will the system work?
Implementation
System delivery

Slide 7
A “Simple” Process for Making Lunch

Slide 8
Identifying business value
Analyze feasibility
Develop work plan
Staff the project
Control and direct project
Planning

Slide 9
Analysis
Information gathering
Process modeling
Data modeling
Analysis

Slide 10
Physical design
Architectural design
Interface design
Database and file design
Program design
Design

Slide 11
Construction
Installation
Implementation

Slide 12
Processes and
Deliverables
Process Product
Planning
Analysis
Design
Implementation
Project Plan
System Proposal
System
Specification
New System and
Maintenance Plan

Slide 13
THE EVOLUTION OF
SYSTEM DEVELOPMENT

Slide 14
What Is a Methodology?
A formalized approach or series
of steps
Writing code without a well-
thought-out system request
may work for small programs,
but rarely works for large ones.

Slide 15
Structured Design
Projects move methodically
from one to the next step
Generally, a step is finished
before the next one begins

Slide 16
Waterfall Development
Method

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

Slide 18
Alternatives to the SDLC
Rapid Application Development
(RAD)
Phased Development
Prototyping
Throw-Away Prototyping

Slide 19
Rapid Application
Development
Critical elements
CASE tools
JAD sessions
Fourth generation/visualization
programming languages
Code generators

Slide 20
Rapid Application
Development Categories
Phased development
A series of versions
Prototyping
System prototyping
Throw-away prototyping
Design prototyping

Slide 21
How Prototyping Works

Slide 22
Throwaway Prototyping

Slide 23
Object-Oriented Analysis
and Design
Attempts to balance emphasis
on data and process
Uses Unified Modeling Language
(UML) for diagramming
Use-case Driven
Architecture Centric
Iterative and Incremental

Slide 24
BASIC
CHARACTERISTICS OF
OBJECT-ORIENTED
SYSTEMS

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

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

Slide 27
The Key to Reusability
Information hiding is the
principle that only information
required to use the object is
available outside the object
Encapsulation is the mechanism
that combines data and
processes in a single object

Slide 28
Class Hierarchy

Slide 29
Inheritance

Slide 30
Polymorphism

Slide 31
OBJECT-ORIENTED
ANALYSIS AND DESIGN
USING UML

Slide 32
UML
The full UML provides 9
separate diagramming
techniques

Slide 33
PROJECT TEAM ROLES
AND SKILLS

Slide 34
Information Systems
Roles
Business analyst
System analyst
Infrastructure analyst
Change management analyst
Project manager

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.

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 concepts
There are five major team roles:
business analyst, systems analyst,
infrastructure analyst, change
management analyst and project
manager.

Slide 37
Expanding the Domain
For complete description of UML
see:
www.rational.com/uml

OOD_ch01.ppt

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