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Phase 4 System Implementation. Chapter 10 – Application development Chapter 11 – Installation and Evaluation. CHAPTER 10. Application Development (Software Engineering). Application Development. Process of creating the programs needed to satisfy IS processing requirements.
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Phase 4System Implementation Chapter 10 – Application development Chapter 11 – Installation and Evaluation
CHAPTER 10 Application Development (Software Engineering)
Application Development • Process of creating the programs needed to satisfy IS processing requirements
Quality Assurance • Objective: • Avoid problems • Detect them as soon as possible • Use Software Engineering to manage and improve quality • ISO certified
Application Development • Review Program documentation • from design phase • Design Program • structure charts, program flowcharts, pseudocode
Structure Charts • Module: rectangle • Data Couple: arrow with empty circle • Control Couple: arrow with filled circle • Condition: line with a diamond
Application Development • Code Program • Write the program instructions (source code) • Distinction between source, object and executable code
Object Oriented App Development • Easier and faster than structured because work is already done in Analysis phase.
Application Development • Test Program • syntax errors, clean compile, desk checking • structured walkthrough , code review • unit test, logic errors, execution errors • test data • debugging • test plan
Application Development • Complete Documentation • Written material that explains what the IS does and how people interact with the system
Testing, Testing, Testing • Logic errors / syntax errors • Unit test • Desk checking • Structured walkthrough • Test data • Link test • test two or more programs together that depend on one another • System test • Stress test
Testing, Testing, Testing • System test • test of entire IS using live data supplied by end user • attempt to process all situations • end user part of system test
DOCUMENTATION • Program documentation • System documentation • Operations documentation • program run sheet • End User documentation • initial learning and ongoing use • user manual, tutorial, on-line help
Application Development • Management approval!!!
CHAPTER 11 SYSTEMS IMPLEMENTATION AND EVALUATION
Systems implementation and evaluation • All software and hardware for new IS is complete and available • First step is to prepare production environment and transfer programs and procedures
Operational and Test Environments • Operational ---Production • Test environment • Separate environments MUST be maintained and strictly controlled
Training Plan • Training of end users takes place in systems implementation and evaluation phase • Planning for training begins during development phase • Everyone who will interact with IS must understand their role in operation of IS
Training Plan • Identify who needs training • Identify specific training needs for each group • Identify who will perform the training • in-house (IS staff or end user) • Vendors • Outside training resources
Training Plan • Train people in groups • Develop separate training programs for distinct employee groups • Consider most effective place • Provide for learning by hearing, seeing, and doing • Prepare training manual or tutorial • Rely on previous trainees
Data Conversion • Activities necessary to transfer operations from old information system to new system • All existing system data is loaded into new IS files or databases
Data Conversion • Automate old manual system, must enter all data • Update old automated system, transfer old system files • Do not relax system controls in order to speed up conversion
System Changeover • Process of putting new IS into production and retiring old system • can be either rapid or slow process • 4 typical changeover methods
CHANGEOVER METHODS • DIRECT CUTOVER • PARALLEL OPERATION • PILOT OPERATION • PHASED CHANGEOVER
DIRECT CUTOVER • Change from old system to new system occurs overnight • least expensive • risk is high (no going back!!!) • must consider timing carefully
PARALLEL OPERATION • Both old and new IS are in full operation for some time • Data generated and collected during parallel period input to both systems • extra code is required
PARALLEL OPERATION • Advantages -- minimize risk • Disadvantages -- cost • both systems are in operation at same time • end users support both systems • extra programs required • May not work for all projects
PILOT OPERATION • First implement new IS for a small part of company • pilot site • direct cutover at that pilot site • smaller group to deal will any problems • WHO
PILOT OPERATION • Less expensive than parallel • More expensive than direct • More risk than direct • Less risk than parallel
PHASED CHANGEOVER • Implement new IS in pieces (modules) • Purchasing first, followed by warehousing …… • Can narrow down any problems introduced overnight to smaller section of modules
PHASED CHANGEOVER • Less expensive than parallel • More expensive than direct • More risk than direct • Less risk than parallel
Post Implementation Tasks • Once new system is operational: • Prepare post implementation evaluation • Deliver a final report to management
POST IMPLEMENTATION EVALUATION • Quality of IS and developmental effort assessed • Verifies that new IS meets specified requirements • evaluation of end product as well as process (within time, budget …) • WHO • WHEN
Evaluation • Accuracy, completeness and timeliness • User satisfaction • System reliability and maintainability • Adequacy of system controls • Hardware efficiency • Effectiveness of Database • Performance of the IT team • Completeness and quality of documentation • Quality and effectiveness of training • Accuracy of cost-benefit estimates and development schedule
FINAL REPORT TO MANAGEMENT • REQUIRED!!! • Signals end of systems development work
FINAL REPORT TO MANAGEMENT • Final version of all system documentation • Planned modifications and enhancements • Recap of systems development costs and schedules • Results of post-implementation evaluation
Ready to move on to… System Operation and Support