System Analysis Flashcards
Corrective
maintenance
Carried out when a bug in the program has been identified. e.g. A piece of software may crash when is used with a particular item of hardware
Adaptive
maintenance
Out to reflect external changes or operate with new hardware / OS e.g. changes to values such as the % rate of VAT or changes to income tax rates will result in changes to software
Perfective
Maintenance
Improving the performance of the software e.g. configuring network management software to improve the performance such as improving access times to data
Alpha Testing
A program is released to a restricted audience of testers within the developer’s own company. Carried out in-house by developers/programmers
Beta Testing
A program is released to a number of prospective customers or general public in exchange for their constructive comments.Carried out by prospective/typical customers
Acceptance
testing
Carried out by the customer to ensure that the system works correctly
Feisability Study
.The summary of an initial investigation to look at the likelihood of creating a new system
Direct
Changeover
Stop using the old system one day and start using the new system the next day
Pros
⦿Requires fewer resources (money / people / equipment) and is simple, provided nothing goes wrong
⦿Where failure would not be catastrophic
Cons
⦿Element of risk particularly if hardware and software are the latest
⦿If system fails then in can be disastrous
Parallel
changeover
Old ICT system is run alongside the new ICT system for a period of time until all the people involved with the new system are happy it is working correctly
Pros
⦿Safest option as if new system fails still has working system
⦿Can compare results and be sure it is working properly
Cons
⦿Lots of unnecessary work (as work is being done twice and is therefore expensive in people’s time)
⦿Adds to amount of planning needed for implementation
Phased
changeover
A program module at a time can be converted to the new system in phases until the whole system is transferred
Pros
⦿IT staff can deal with problems caused by program modules before moving onto new modules
⦿Staff training can be done in stages
Cons
⦿Only suitable for systems consisting of separate program modules
⦿Slower to get system up and running compared to other methods like direct or parallel
Pilot
changeover
This method is ideal for large organisations that have lots of locations or branches where the new system can be used by one branch and then transferred to other branches over time
Pros
⦿Difficulties identified in one area can be resolved and manged in next area
⦿Implementation is on much smaller scale
Cons
⦿Takes longer to implement the system in all the branches
⦿Department doing the pilot may not have a backup if things go wrong
Methods of investigation
⦿Study existing system documentation.
⦿Carry out a questionnaire of staff.
⦿Interview staff
⦿Observe the current system in practice.
User Documentation
Describe how to use the system to new users. Contains:
⦿Detailed instructions how to navigate, input data …
⦿Actions to take when errors occur
⦿Installation guide
Maintenance documentation
Used by developer to describe how code & system can be updated and understood.
⦿Pseudo-code/ flowcharts
⦿Annotations
⦿Data dictionary with descriptions of structure of data used in system
Backup and recovery procedures
How and when data is backed up and how to recover data in event of loss. Contains:
⦿When where data is backed up
⦿Procedures to follow backup
⦿Instructions /steps to recover data after loss.
