Topic 1 Flashcards
Identify the context for which a new system is planned
• What is the problem that the new system is going to solve?
• Alternative solutions
• Staffing: numbers, training
• Cost
• Time
• Compatibility with existing systems
• Infrastructure requirements, eg existing network
Bespoke (custom-made) software versus off-the-shelf
Describe the need for change management (8)
• Communication of the need for and benefits of change
• Users may require training
• Recruitment may be necessary to bring in suitable skillsets
• Stakeholder support
• Planning, milestones, completion date
• Dependencies between project stages/components
• Compatibility between old system and new system
Testing
When two businesses merge, their computer systems may be incompatible with each other in terms of
- Operating systems
- Data formats
- Hardware
Legacy systems are not always immediately replaced because
- They might still work well
- It might be too costly to develop a new system
- Perhaps users are comfortable and retraining would be too much of an upheaval (e.g. Nokia and Microsoft are still two separate entities & Pixar and Disney)
- Perhaps nobody understands how it works!
A legacy system is…
an old technology or computer system, often one that is inherited by one company when another company is bought out
Software-as-a-service is …
the idea that your software needs are provided by a remotely hosted system, that is managed by an ASP (Application Service Provider), rather than having your own hardware and technical staff. Most organisations have some mix of in-house and outsourced systems.
• This point is about whether you should buy hardware for your system and manage it yourself (in-house), or rent the hardware and have someone else host and manage it (outsourced)
List four installation processes of a new system
- Parallel running
- Pilot running
- Phased conversion
- Direct changeover
Outline parallel running and its advantages and disadvantages
Old system and new system at the same time.
• Very low risk because even if new system doesn’t work the old system is still there to cope with problems.
_____________________
• May need extra employees to work both systems at the same time. More work and higher salary costs.
• Twice as long when doing things like data entry
Outline pilot running and its advantages and disadvantages
New system used by a some limited group, perhaps one office, rather than the whole company.
• Low risk because old system is still running.
• Cheaper than parallel running in terms of extra staff and extra work required.
_____________________
• Risk that new system problems won’t be detected because number of users and amount of data is unrepresentative.
• Not all possible bugs may be picked up
Outline phased conversion running and its advantages and disadvantages
Going from old system to new system in steps.
• Longer period of time in which employees can learn to use the new system.
• Low risk of large problems because each phase implies only a small change.
______________________
• Not always possible. Some systems are all or nothing and cannot be introduced in stages.
Outline direct changeover running and its advantages and disadvantages
“Big bang” or “flicking the switch”. Going from old system to new system overnight.
• Lowest cost if all goes well.
____________________
• Substantial risk from problems with the new system because old system is no longer there to rely on.
• If there is inadequate training before the new system is switched on, there will be a large risk
Data migration is…
the process of moving data from one system to another, usually an older system to a newer one
Issues that can arise from data migration are
- Incompatible file formats, data structures, validation rules
- Incomplete data transfer
- International conventions on dates, currencies and character sets
Data often has to undergo a _________ process before it can be loaded into the new system.
conversion
List and outline 9 types of testings
- Debugging: Ongoing. Happens during development
- Alpha testing: The first stage of testing, done by the programmers themselves
- Beta testing: Later testing, done by future users when the system is almost finalised
- Black-box testing: Testing what the system is supposed to do, from the point of view of the user, with no knowledge of how the program does what it does
- White-box testing: Testing the system from the point of view of the programmer, with full knowledge of how it does what it does
- Unit testing: Testing the modules or components of the system separately
- System testing: Testing the system as a whole
- Acceptance testing: The last testing phase once the system is delivered to the user
- Automated testing: Using software to test software
Describe the importance of user documentation
- Non-technical (as opposed to system documentation)
- Installation, operation, troubleshooting
- Sample data and screens
- One of the biggest difficulties with a new system is a userbase that is unwilling or unable to adopt the new system (old habits die hard)
- Good user documentation can go a long way to making a new system successful by easing the transition
