1.4 Project Life Cycle
Now that we understand what projects are and know their characteristics, categories, and types, let us look at project life cyclesproject life cycles: A series of phases that a project passes through from its start to its completion.
Project Completion Life Cycle
In Figure 1.5, the J-shaped project life cycle curve is represented, with time running from left to right along the horizontal x-axis. The vertical y-axis represents the percent (%) of the project that is completed, with zero completion at the bottom to 100% completed towards the top. This project is characterized by a slow start and a fast finish. Weddings, seasonal theatre performances, or annual tradeshows may fit this curve. These are projects that start slowly, progressively develop at a measured rate during most of the project, and then accelerate to completion toward the end.

The S-shaped project life cycle curve (in Figure 1.6) starts out at a moderate pace, accelerates during the Executing phaseExecuting phase: The part of a project where directing, managing, performing, and accomplishing the project occurs; providing deliverables and providing work performance information.
Enterprise software may also follow this curve because there are often bug fixes and configuration adjustments that take many months to resolve completely, so closing out the project can take a long time. For large organizations, the software application may roll out by department, and this can take months or years to complete.
Project Resources Life Cycle
Figure 1.7 shows the S-shaped curve again, except this time, the y-axis represents cost (budgetbudget: The approval estimate for the project or any work breakdown structure (WBS) component or any scheduled activity.

In the project cost life cycle representation in Figure 1.7, it is clear that most of the costs of a project are incurred in the Executing phase of the project. It is also worth noting that for larger projects, expenses are still incurred after the project output or outcome has successfully been delivered to and accepted by the customer. Topic 10 will address the Closing phaseClosing phase: The process of finalizing all activities for the project, phase, or contract.
