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System Implementation 1
System Implementation
System Implementation 2
Agenda
• System Implementation
• Testing
• Prototyping
• Installation
• Post-implementation
System Implementation 3
System Implementation
See(analyze)
Think(Design)
Say(Build)
Do(Use)
System Implementation is concerned with puttingthe products of IT “research and design” in the handsof users. Normally, this entails building and testing
software and hardware-software systems.
Building and testing are usually separate activities,and usually they follow separate analysis and design
Activities, but they can all be joined together into a prototyping exercise.
System Implementation 4
Testing
• Unit testing: testing of individual programs• System testing: testing the entire system of
programs• Volume testing: testing the application with
a large amount of data• Integration testing: testing all related
systems together• Acceptance testing: conducting any
tests required by the user
System Implementation 5
Testing
• Philosophy: Anything a technical person builds for a non-technical person needs to be tested.
• Method: A variety of tests are performed by technical people and ultimately by users
• Only when all tests have been passed, then application is ready for use
System Implementation 6
Prototyping
• Philosophy: Users know what they want, but the knowledge might be tacit, i.e., they might not be able to articulate needs
• Method: Tease out user requirements by showing them examples of what they might want, homing in step by step towards a satisfactory example. This is the equivalent of continuous testing
• This satisfactory example is then worked on by craftspeople to make it good.
System Implementation 7
Prototyping Pros and Cons
• Pros Directly engages the user User needs are visited and viewed directly Result passes the curb appeal test
• Cons Really only useful when user is experienced Can be very costly for many iterations Analyst, user must be patient with each other Result might be over-engineered to user
requirements that aren’t “real”.
System Implementation 8
Prototyping
See Think Say Do
(no surprise)
Is it good enough?
Yes…optimize, please
No…try again, please
System Implementation 9
PrototypingWe do this until the user is satisfied or until the systems analyst dies
ExpertImple-
mentation
System Implementation 10
Installation
• The process of physically placing the computer equipment on the site and making it operational
• Normally the manufacturer is responsible for installing computer equipment
• Someone from the organization (usually the IS manager) should oversee the process
System Implementation 11
Start-Up
• The process of making the final tested information system fully operational
• Going from A (no system) to B (using system) is a major dislocation, apt to cause up to many months of decreased productivity before benefits occur
• The way to go A → B depends on the situation:
System Implementation 12
Four Choices
• Direct conversion (also called plunge or direct cutover – “Black Monday” effect)
• Phase-in approach (function by function; perhaps department by department)
• Pilot start-up (a test area, function or department)
• Parallel start-up (where mission critical information is required or involved, where absolutely reliable service is needed)
System Implementation 13
Four Choices
• Plunge Cheap, but rarely cheerful• Phase-in Best if independent functions are
being implemented; disruption is contained to one area.
• Pilot Small group of users is impacted; generally cooperative users who can accurately inform management about what is wrong and right.
• Parallel Absolutely necessary if system continuity is required. Very expensive. Can present management problems.
Goal is cost and
time saving
Compromise between
learning and cost saving
Goal is to maximize learning
Goal is reliability and
continuity. Works only if
current system is functional
System Implementation 14
Post-Implementation
• User Reactions Great! It Doesn’t Work; I don’t want it Help me Am I using it right?
• What Next? Improvement: make it work right! Enhancement: make it work better!! Replacement: get rid of it!!!