Systems Maintenance

Corrective

‘Bugs' (1) which may not have been identified during the testing process (1) become apparent when the system is operating in a live environment (1)

Perfective

• Users may, after a period of time (1) find a particular aspect of the software unsatisfactory (1) e.g. tables may be difficult to format for printing (1)

• A security issue (1) e.g. a virus threat (1) may emerge which means that the system requires an extra level of protection (1)

• The software provider may discover a way to make the application run more efficiently (1) e.g. floating editing windows (1)

Adaptive

• Changes in the business environment (1) e.g. change in legislation (1) may mean that the software is required to perform tasks it wasn't originally designed for (1)

• New software or hardware may be purchased (1) the integration of which requires changes to existing systems.