IS Analysis and Design
SDLC
Systems Development Life Cycle
Break problems into management
review stages
 Control cost and time
 Works best with well understood
systems
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Initial Investigation
What is the system supposed to do
and what priority should we give it?
 On IS budget
 Memo or oral
 Define user’s general expectations
 Rough cost
 Assign priority
How do we find problems?
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Surveillance
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Frameworks
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Reaction
Opportunistic
Competitive strategy
Customer resource life cycle/future perfect
Object System rather than IT system
SDLC Waterfall
Identify Problem
Analyze Current System
Determine Information Requirements
Design Technology Requirements
Develop, Test, & Validate
Install
Evaluate & Maintain
General Analysis
Specify logical
system
requirements
General Systems Analysis
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Understand the current system
Be sure you don’t omit essential features
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Obtain detailed specifications of
expected functions
Operations level requirements
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Provide specifications for IT
developers to design from
General Analysis
Gather information
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Existing documentation and actions
Interviews and questionnaires
Structured interviews
Define current decision making process
Isolate current deficiencies
Identify necessary controls and checks
General Analysis
Determining Information
Requirements
 Define all functions of the system
Most systems should be cross-functional
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Avoid information overload
Many managers do not know what
information they need
General Analysis
Determining Information
Requirements
 Give users models of new systems
Prototypes and models
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Reconcile user conflicts
Joint Application Design
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Structure the interview process
BSP, Critical Success Factors, Ends
Means
Include
Complete conceptual data model
with table instance data, constraints,
and volumes
 Complete logical data flow analysis
with module specifications
 Conceptual network design with
volume requirements
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General Analysis
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Is this an information system or a
reengineering project?
Reengineering requires a mandate to
change the way you do business, and
requires a major commitment from all
participants. Most information systems
are written to support existing
processes.
System Design
Identify Problem
Analyze Current System
Determine Information Requirements
Design Technology Requirements
Develop, Test, & Validate
Install
Evaluate & Maintain
Detailed Conceptual and
Physical Design
Computer system structure and
module specification
Input/Output design
 Logical data structures and views
 Data dictionaries
 System logic definitions
 System flow
 Network design charts
 Documentation
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Identify Problem
Analyze Current System
Determine Information Requirements
Design Technology Requirements
Develop, Test, & Validate
Install
Evaluate & Maintain
System Development
Build it
Development
Structured Code
 CASE tools
 Code generators
 Rapid Application Development
 Object Oriented development
 Prototypes
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Testing
Walkthroughs and code inspection
 Application test
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Unit test - each program
 System test - whole system together
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Processes and user acceptance
Identify Problem
Analyze Current System
Determine Information Requirements
Design Technology Requirements
Develop, Test, & Validate
Install
Evaluate & Maintain
Installation
Introduce into the
organization
Implementation

Conversion
Direct
 Phased
 Pilot
 Parallel
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Training
 Operations acceptance
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Identify Problem
Analyze Current System
Determine Information Requirements
Design Technology Requirements
Develop, Test, & Validate
Install
Evaluate & Maintain
Maintenance
Everything after
acceptance
Proposal
How Should we do
it?
Proposal (Feasibility Study)
Formal report
 On user budget
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What should we do?
 How should we do it?
 What should it cost?
 How will we use it?
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Format:
May include these sections
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Title page
Table of contents
Executive summary
Problem statement
Analysis of alternatives
Cost and benefits
Recommendation
Request for authorization
Appendix
Executive Summary
One to three page summary of the
report, including costs and
recommendations.
Objective: Get the decision maker to
refer the rest of the study for
detailed analysis.
Problem Statement
Simple statement of what is to be
accomplished and any major
constraints.
Analysis
Describes what has been done
 Indicate alternatives considered
 Include “do nothing” option and
costs
 Consider purchased products and
outsourcing
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Analysis (cont.)
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Technical feasibility
Do we have the technology to
accomplish this task?
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Economic feasibility
Do the benefits of this project outweigh
the costs at this time?
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Operational feasibility?
Does this system fit into the way we
want to do business?
Costs and Benefits
Costs are easier to identify than
benefits
 Include intangible and tangible
costs
 Business benefits include reduced
costs and increased revenue
 Include competitive positioning
 Consider business focus: low cost,
differentiation, focus
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Recommendation
Choose the best option. Consider
business as well as technical
arguments.
 You may leave some options or a
choice between equivalent systems
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Request for Authorization
Ask permission to continue to next
stage
 Estimate cost and schedule for next
stage, as well as total project costs.
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Appendices
Include
Interview notes
 Document summaries
 Diagrams and specifications
 Cost details
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You may choose not to circulate the
appendices with the document if
they are long.