Understanding Project Life Cycles

The project manager and project team have one shared goal: to carry out the work of the project for the purpose of meeting the project's objectives. Every project has an inception, a period during which activities move the project toward completion, and a termination (either successful or unsuccessful). Taken together, these phases represent the path a project takes from the beginning to its end and are generally referred to as the project life cycle.

The project life cycle is often formally divided into phases that describe common activities as the project matures. The activities near the beginning of a project look different from activities closer to the end of the project. Most projects share activity characteristics as the project moves through its life cycle. You might see several questions on the exam that ask you to compare different phases in a project's life cycle. In general, here are the common comparisons of early and late project life cycle activities:

• The least is known about the project near its beginning As the project matures, more is learned about the project and the product it produces. This process is called progressive elaboration. As you learn more about the project, all plans and projections become more accurate.

• The level of uncertainty and risk is the highest at the beginning of a project As more is learned about the project and more of the project's work is completed, uncertainty and risk decrease.

• Stakeholders assert the greatest influence on the outcome of a project at the beginning After the project starts, the stakeholder influence continually declines. Their influence to affect the project's outcome is at its lowest point at the end of the project.

• Costs and personnel activity are both low at the beginning of a project, are high near the middle of the project, and tend to taper off to a low level as the project nears completion.

• The cost associated with project changes is at its lowest point at the project's beginning No work has been done, so changing is easy. As more and more work is completed, the cost of any changes rises.

One of the more important relationships to understand throughout the project life cycle is the relationship between project knowledge and risk. As stated earlier, knowledge of a project increases as more work is done due to progressive elaboration, and risk decreases as the project moves toward completion. Figure 1.2 depicts the relationship between knowledge and risk:

Figure 1.2. Project risk versus knowledge of project.

Another important relationship present in a project's life cycle is the relationship between the declining influence of stakeholders on the outcome of a project and the cost of changes and error corrections. Because little or no work has been accomplished near the beginning of a project, changes require few adjustments and are generally low in cost. At the same time, stakeholders can assert their authority and make changes to the project's direction. As more work is accomplished, the impact and cost of changes increase and leave stakeholders with fewer and fewer options to affect the project's product. Figure 1.3 shows how the influences of stakeholders and cost of changes are related to the project life cycle:

Figure 1.3. Stakeholder influence and cost change impact through the life of a project.

Although all projects are unique, they do share common components or processes that are normally grouped together. Here are the generally accepted process groups defined by PMI (we'll cover each of these process groups in the coming chapters):

• Initiation

• Planning

• Executing

• Controlling

• Closing

Moving from one phase in the life cycle to another is generally accompanied by a transfer of technical material or control from one group to another. Most phases officially end when the work from one phase is accepted as sufficient to meet that phase's objectives and is passed onto the next phase. The work from one phase could be documentation, plans, components necessary for a subsequent phase, or any work product that contributes to the project's objectives.