In order to develop a new system it is important to follow a very distinctive series of steps. The systems lifecycle is the steps that every system must follow. The deliverables at the end of each step are dependent on which methodology is followed but the steps, or stages, are always the same.

We start at the beginning of the systems lifecycle which is the problem definition. Then each stage is followed in order till be get to evaluation. At this stage, when we ask how the project went after its completion, there could be a chance that new systems are identified which need to be added on or produced as separate systems. This is why it is known as the lifecycle. It could be done more than once for a given system. Consider Microsoft windows. When a new operating system is produced the next one will be planned. This is so it can take advantage of knowledge gained during the project as well as take advantage of new technologies.