Introduction to Systems
Analysis and Design
Lecture 1
Courtesy
Subhasish Dasgupta
ISTM 280, GWU
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Key Ideas
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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.
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2
Key Ideas
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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.
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The Systems Development Life Cycle:
Major Attributes of the Lifecycle
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The project
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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
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4
Project Phases
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Planning
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Analysis
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Who, what, when, where will the system be?
Design
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Why build the system?
How will the system work?
Implementation
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System delivery
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Planning
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Identifying business value
Analyze feasibility
Develop work plan
Staff the project
Control and direct project
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Analysis
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Analysis
Information gathering
Process modeling
Data modeling
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Design
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Physical design
Architectural design
Interface design
Database and file design
Program design
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Implementation
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Construction
Installation
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Processes and Deliverables
Process
Product
Planning
Project Plan
Analysis
System Proposal
Design
System
Specification
Implementation
New System and
Maintenance Plan
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10
Systems Development Methodology:
What Is a Methodology?
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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.
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11
Structured Design
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Projects move methodically from one to the
next step
Generally, a step is finished before the next
one begins
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Waterfall Development Method
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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
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Parallel Development
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Alternatives to the SDLC
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Rapid Application Development (RAD)
Phased Development
Prototyping
Throw-Away Prototyping
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Rapid Application Development
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Critical elements
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CASE tools
JAD sessions
Fourth generation/visualization programming
languages
Code generators
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Rapid Application Development
Categories
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Phased development
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Prototyping
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System prototyping
Throw-away prototyping
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A series of versions
Design prototyping
Agile Development
Extreme Development
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How Prototyping Works
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Throwaway Prototyping
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Selecting the Appropriate Methodology
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Clarity of User Requirements
Familiarity with Technology
System Complexity
System Reliability
Short Time Schedules
Schedule Visibility
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Information Systems Roles
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Business analyst
System analyst
Infrastructure analyst
Change management analyst
Project manager
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Object-oriented approach –
Classes and Objects
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Class – Template to define specific instances
or objects
Object – Instantiation of a class
Attributes – Describes the object
Behaviors – specify what object can do
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Basic Characteristics of Object Oriented
Systems
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Classes and Objects
Methods and Messages
Encapsulation and Information Hiding
Inheritance
Polymorphism and Dynamic Binding
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Object Oriented Systems Analysis and
Design
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Use-case driven
Architecture Centric
Iterative and Incremental
The Unified Process
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