information system applications system development life cycle
TRANSCRIPT
- Slide 1
- INFORMATION SYSTEM APPLICATIONS System Development Life Cycle
- Slide 2
- PRIMARY OBJECTIVES n Explain the phases in the system development life cycle n Identify the guidelines for system development n Discuss the importance of project management, feasibility assessment, information gathering techniques and documentation
- Slide 3
- PRIMARY OBJECTIVES (cont.) n Describe how structured tools such as data flow diagrams and entity- relationship diagrams are used in analysis and design n Identify program development as part of the system development life cycle
- Slide 4
- WHAT IS THE SYSTEM DEVELOPMENT LIFE CYCLE ? n Organized set of activities used to guide those involved through the development of an information system
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- Phases in the system development life cycle (SDLC) n Planning n Analysis n Design n Implementation n Support
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- System Life Cycle System Study Design Programming Installation Evaluate+ Maintenance Project definition
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- Who participates in the system development life cycle? n Project team n Users n Information systems personnel n Systems analyst n Programmers n Steering committee
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- Project management n Scope n Project plan n Gantt chart
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- Feasibility assessment n Operational feasibility n Will the system work in their environment? n Schedule feasibility n Are project deadlines reasonable? n Technical feasibility n Do they have the resources to support the system people, hardware, software? n Economic feasibility n Does it make economic sense?
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- Documentation n Project notebook - entire collection of documentation n Project dictionary - an automated project notebook
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- Data and information gathering techniques n Reviewing current system documentation n Observation n Questionnaires n Interviews n Joint-application design (JAD) sessions n Researching
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- Analysis Phase n Activities/Tasks: n Fact Gathering n Data Flow Diagrams (DFD) : Used to document the flow of information through an information system and identify problem areas.
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- Analysis Phase n Activities/Tasks: n Process Description: Used to define the internal workings of a process on the DFD. n Data Dictionary : Used to document the data definitions and formats.
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- Analysis Phase n Activities/Tasks: n Data Modeling: Designing the necessary databases and specifying how they may be accessed. n System Modeling: Using requirements to create actual plans for the new information system. n Project Management: The process of controlling the project to ensure schedules are met, estimates are updated, and costs are contained.
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- Detailed Analysis n Study the current system n Identify the users wants, needs, and requirements n Present alternative solutions
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- Detailed Analysis n Structured Analysis and Design Tools Data Flow Diagrams Structured Analysis (HIPO charts) Work Break Down Structure Entity Relationship Diagrams Decision Tables Decision Trees Data Dictionary
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- Design phase activities n Covert DFDs into structure charts (Hierarchical diagram of program modules) n User Interface design (Input/Output) Forms n Data base design n Structured walkthroughs n Design Testing Procedures
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- Detailed Design of Software n Database design Data store in DFD Logical modeling (ER - diagrams) Normalization (Data redundancy & integrity) n Data security n Program Design Program Specification package System Flowchart
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- Detailed Design of Software n CASE tools Computer-aided software engineering (CASE) n Graphics n Prototyping n Quality assurance n Code generators
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- Detailed Design n Quality review n Necessary to double-check assumptions and design n Structured walkthrough
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- IMPLEMENTATION PHASE SDLC #4 Develop programs n Install and test the new system n Train and educate users n Convert to the new system
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- Develop programs n Program development life cycle (PDLC) Analyze Design the programs Code Test the programs Maintain the programs
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- Implementation Phase n Install and test the new system n System test - verify that all programs work and work together n Integration test - verify that an application works with other application in the system n Acceptance test - performed by users with real data n Types of testing varies
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- IMPLEMENTATION PHASE SDLC #4 n Train and educate users Classroom-style lectures One-on-one sessions User manuals CAI
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- IMPLEMENTATION PHASE SDLC #4 n Convert to the new system n Direct n Parallel n Phased n Pilot conversion old New old Old New
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- SUPPORT PHASE SDLC #5 n Conduct post-implementation system review n Identify errors n Identify enhancements n Monitor performance
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- n Questions and comments?