Chapter 8 – System Implementation Flashcards
Planning for System Implementation
- Schedule planning
- Site preparation / renovation
- Hardware installation
- Software installation
- Data conversion
- System changeover
- System testing
- Training
Data Conversion
• During data conversion:
- Existing data is loaded into the new system
Data Conversion Strategies
• Old system:
- Capable of exporting data in an acceptable format or standard format for the new system
~ Such as ASCII or ODBC
• Unavailability of a standard format:
- Develop a program to extract the data and convert it
• Requires additional data item
- Require manual entry
Data Conversion Security and Controls
• Ensure that: - All system control measures are in place and operational to: ~ Protect data from unauthorized access ~ Prevent erroneous input • Some errors will occur • Essential: - New system be loaded with: ~ Accurate ~ Error-free \+ Data
System Changeover (*)
• Process of putting the new information system online and retiring the old system • 4 changeover methods: - Direct cutover - Parallel operation - Pilot operation - Phased operation
Direct Cutover (*)
• Old system terminates and the new system takes over immediately
• Least expensive method
- Because the company operates only 1 system at a time
• Involves more risk
• Chosen for implementing commercial software packages
Parallel Operation (*)
• Both new and old information systems:
- Operate side-by-side
~ Until the company is satisfied that the new system operations correctly
~ Then the old system is terminated
• Easy to verify:
- That the new system is working properly under parallel operation
• Running both systems might place a burden on the operating environment
- And cause processing delay
• Not practical if:
- The old and new system are incompatible technically
• Inappropriate when:
- Two systems perform different functions
Pilot Operation (*)
• The entire new information system is implemented but:
- Only at a single location called a pilot site
• After the system proves successful at the pilot site:
- It is implemented in the rest of the organization
~ Using the direct cutover method
• Old system continues to operate for the organization
• Combination of:
- Parallel operation
- Direct cutover methods
Phased Operation (*)
• New system is implemented in stages - Not modules • Not possible to use - Unless the system can be separated easily into: ~ Logical modules or phases • Give a part of the system to all users • Risk of errors or failure: - Limited to the implemented module only • Less expensive: - Than full parallel operation
System Testing (*)
- Syntax errors, Desk checking, Logic errors, Structured walkthrough / code review (guide), Design walkthrough
- Unit Testing
- Integration Testing
- System Testing
- Acceptance Test
Unit Testing (*)
• Testing of: - Individual programs or modules • Test: - Data - Programs that interact with other programs and files individually • Stub testing - Writing a dummy code / Using a dummy component ~ To simulate the behaviors of software components/modules depending what module it is undergoing from • Test plan: - Project manager / Designated analyst ~ Reviews the final test results • People involved: - Programmers
Integration Testing / Link Testing (*)
• Testing two or more programs that depend on each other
• Testing the programs independently:
- Does not guarantee that the data passed between them is correct
• Testing sequence:
- Should not move to the integration stage
~ Unless it has performed properly in all unit tests
• People involved:
- Programmers from the different modules
System Testing (*)
• Tests the entire system
• Objectives:
- Perform a final test of all programs
- Verify that the system:
~ Will handle all input data properly
+ Both valid and invalid
~ Components are integrated properly
~ Actual processing situations will be handled correctly
- Ensure that:
~ The IT staff has the documentation and instructions needed to operate the system properly
~ Backup and restart capabilities of the system are adequate
- Demonstrate that:
~ Users can interact with the system successfully
- Confirm that the information system can:
~ Handle predicted volumes of data in a:
+ time and efficient manner
• People involved:
- Technical system tester
Acceptance Tests (*)
• Conduct to determine whether:
- The system is ready for release
• User must test the system to find out whether:
- The application meets the business needs
• Once completed and approved:
- The program will then be delivered to production
Training Plan (how)
• Identify who: - Should receive training - What training is needed • 3 main groups for training: - Users - Managers - IT staff • Determine how the company will provide training
