Topic 1 - System Fundamentals Flashcards
3 difficulties in changing software systems
- Users don’t like change
- Expensive
- Data loss
4 ways of changing to a new system
- Direct changeover
- Parallel
- Pilot
- Phased
Direct changeover
When the old system is stopped and replaced completely by the new system
Parallel
When both the new and old system run simultaneously and data is entered into both
Pilot
New system tested with small part of the organization, bugs are fixed and then the system is expanded into the rest of the organization
Phased
When the new system is introduced in phases and the old system gradually phases out
2 pros and 1 con of Direct Changoeover
Pros:
- Quick changeover
- New system is available immediately
Con:
- There is no backup system in case of failure
2 pros and 1 con of parallel changeover
Pros:
- There is a backup system in case of one system failing
- Output from both systems can be compared to verify functionality of the new system
- Expensive
2 pros and 1 con of pilot changeover
Pros:
- Staff who are part of the pilot can train others
- All features can be tested before it is implemented throughout the whole organization
Con:
- No backup for pilot group in case of failure
2 pros and 1 con about Phased Conversion
Pros:
- Allows people to get used to new system
- Training can be done in stages
Cons:
if system fails, no backup for that part of system
Data migration
Moving data from one system to another
3 possible problems with data migration
- Incompatible file formats
- Validation rules
- Different currencies
Legacy System and 1 example
Old technology, computer system or application that is no longer supported. E.g. Windows XP
3 characteristics of traditional software/local software
- One-time fee
- Used on one computer
- Free trial not available
3 characters of SAAS/Remote software
- Subscription fee
- Use on any computer via internet
- Free trial often available
