System DevelopmentInformation Systems for
Management 1
Chapter 9Chapter 9
System Development System Development
Outline
System Life Cycle (definition and phases)
System Planning (Automation, Business Process
Reengineering, Quality improvements -
Benchmarking)
System development methodologies
Installation/conversion methods
Systems success & risk factors
System DevelopmentInformation Systems for
Management 2
System DevelopmentInformation Systems for
Management 3
System Life Cycle
Installation
These activities/phases can be run in sequence or in iteration.
- Waterfall (structured) methodology
- Rapid methodologiesCo
nstr
uctio
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Systems Planning
System DevelopmentInformation Systems for
Management 4System DevelopmentInformation Systems for
Management 4System DevelopmentInformation Systems for
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A Rapid Methodology - Prototyping
Strengths Weaknesses
Rapid and relatively inexpensive Inappropriate for large complex systems
Useful when requirements are uncertain or when end user interface is critical
Can gloss over steps in analysis, documentation and testing
Promotes user involvement
• An alternative to sequential development of systems
• Steps: • Identify basic user’s requirements• Develop an initial prototype• Test prototype & learn from users• Revise & enhance prototype
System DevelopmentInformation Systems for
Management 5
What organizational changes can be accomplished with new system:
Automation of manual tasks
Business Process Reengineering (BPR) - radical change of organization; process efficiency in focus
Quality improvements (Benchmarking – test of compliance with standards)
Systems Planning
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Systems AnalysisAnalysis of organizational needs to be met with an information system focusing on
1. data/information as part of jobs and tasks and on data transformation - remember your entity-relationship diagrams? 2. processes working with data
Data analysis: define Information NeedsIdentifies who needs what information, and
when, where and how it is neededCollect business documentation, interview users & managers
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Systems Design
Create IT-based solution for meeting organizational and
information needs
Design encompasses:
Data (usually some database)
Processes applied to data (functionality)
User Interface
Programming/Construction follows (can be putting
together of purchased software)
System DevelopmentInformation Systems for
Management 8
Testing
Testing – assessing quality of the developed system
Kinds of tests run based on small to large logic:
Unit testing (test each program)
System testing (tests IS as a whole; e.g., overload
the system)
Acceptance testing (final testing, evaluated by users)
System DevelopmentInformation Systems for
Management 9
Installation Methods
Direct cutoverNew system completely replaces old one
Parallel installationOld and new system used until the new proves reliable
Phased installationNew system introduced in stages by function
Pilot installationVariation of Phased - new system introduced to a limited area of the organization
System DevelopmentInformation Systems for
Management 10
Production Stage and Maintenance
System is being used for organizational needs
Operate the system
Evaluate the system
Modify the system as needed (Maintenance; e.g.,
larger data
storage needed or queries answering new questions)