Project Life Cycles

Most, if not all, projects go through a life cycle that varies with the size and complexity of the project. On medium to large projects the life cycle will generally follow the following pattern:

Items 7 and 8 are not usually included in a project life cycle where the project ends with the issue of an acceptance certificate after the performance tests have been successfully completed. Where these two phases are included, as, for example, with defence projects, the term extended project life cycle is often used.

The project life cycle of an IT project may be slightly different as the following list shows:

Running through the period of the life cycle are control systems and decision stages at which the position of the project is reviewed. The interfaces of the phases of the life cycle form convenient milestones for progress payments and reporting progress to top management, who can then make the decision to abort or provide further funding. In some cases the interfaces of the phases overlap, as in the case of certain design and construct contracts, where construction starts before the design is finished. This is known as concurrent engineering and is often employed to reduce the overall project programme.

As the word cycle implies, the phases may have to be amended in terms of content, cost, and duration as new information is fed back to the project manager and sponsor. Projects are essentially dynamic organizations that are not only specifically created to effect change, but are also themselves subject to change.

On some projects it may be convenient to appoint a different project manager at a change of phase. This is often done where the first four stages are handled by the development or sales department, who then hands the project over to the operations department for the various stages of the implementation and completion phases.

When the decommissioning and disposal is included, it is known as an extended life cycle, since these two stages could occur many years after commissioning and could well be carried out by a different organization.

While all institutions associated with project management stress the importance of the project cycle, both BSI and ISO preferred describing what operations should be carried out during the various phases, rather than giving the phases specific names.

Different organizations tend to have different descriptions and sequences of the phases, and Figure 11.1 shows two typical life cycles prepared by two different organizations. The first example, as given by APM in their latest Body of Knowledge, is a very simple generic life cycle consisting of only six basic phases. The second life cycle shown, as formulated by the Ministry of Defence (MoD), clearly shows the phases required for a typical weapons system, where concept, feasibility, and project definition are the responsibility of the MoD, design, development, and production are carried out by the manufacturer, and in-service and disposal are the phases when the weapon is in the hands of the armed forces.

The diagram also shows a calendar scale over the top. While this is not strictly necessary, it can be seen that if the lengths of the bars representing the phases are drawn proportional to the time taken by the phases, such a presentation can be used as a high-level reporting document, showing which phases are complete or partially complete in relation to the original schedule.

The important point to note is that each organization should develop its own life cycle diagram to meet its particular needs. Where the life cycle covers all the phases from cradle to grave as it were, it is often called a programme life cycle, since it spans over the full programme of the deliverable. The term project life cycle is then restricted to those phases that constitute a project within the programme (e.g., the design, development, and manufacturing periods).

Figure 11.2 shows how decision points or milestones (sometimes called trigger points or gates) relate to the phases of a life cycle. At each gate, a check should be carried out to ensure that the project is still viable, that it is still on schedule, that costs are still within budget, that sufficient resources are available for the next phase, and that the perceived risks can be managed.

Figure 11.3 shows how the life cycle of the MoD project shown in Figure 11.1 could be split into the project life cycle, i.e., the phases under the control of the project team (conception to production), the product life cycle, the phases of interest to the sponsor, which now includes the in-service performance, and lastly the extended life cycle, which includes disposal. From the point of view of the contractor, the project life cycle may only include design and development and production. It can be seen therefore that there are no hard-and-fast rules as to where the demarcation points are, as each organization will define its own phases and life cycles to suit its method of working.