Introduction
All things have a beginning, a middle and an end. And Information Technology (IT) is no different. Indeed it could be argued that IT sees more rapid change than many other technologies. Think how many 'upgrades' have happened with your favourite software.
The System Life Cycle (SLC)
The SYSTEM LIFE CYCLE is a process of stages which occur during the development of a new ICT system.
The SLC consists of the following stages:
1-Definition:
2- Investigation and analysis:
During this 'investigation and analysis' phase they will carry out very detailed investigations in order to fully understand the current system and the proposed new system.
3- Design:
This is the Design phase of the project. It is about planning the project in detail so that that system will meet user requirements.
4- Implementation:
Once the design stage has been completed the software developers can begin to write the code and actually develop the new system.
The system could either be completely bespoke with every line of code being written by specialist programmers or it could be developed from an 'off-the-shelf' application which is then customised.
5- Testing:
A team of testers will have been chosen to test the system. They are known as beta testers. Their role is to check that the system does everything exactly as specified in the system and user specification.
6- Installation:
The system has been developed and tested. It is working correctly and doing everything that was agreed during the design stage. The business is waiting in eager anticipation for the new system to be handed over to them.
7- Documentation:
The development of the user documentation is left until after the testing phase is complete. If it is created beforehand, parts of the system could change as a result of faults being discovered.User documentation is provided to the user which gives an overview of how to use the system.
8- Evaluation:
This next stage is called the 'Evaluation phase'. The evaluation stage looks at the overall project and considers how things went.
9- Maintenance:
This phase continues for the lifetime of the system. The technical documentation is essential to support the maintenance stage.
There are three kinds of maintenance needed:
- Corrective maintenance
- Adaptive maintenance
- Perfective maintenance
