According to Gray and Larson (2008), a project life cycle typically passes through four stages. These four stages include defining, planning, executing and delivering. It recognizes that projects have a limited life span and that there are predictable changes in level of effort and focus over the life of the project.
I believe it crucial for a project to be successful on all fronts to go through all stages of the project life cycle. For example, the defining stage sets the project’s specification and establishes objectives, responsibilities are assigned, and teams are formed. To not do so leaves teams and personnel in the dark, so to speak. The planning stage is also important because it includes what the project will entail, its schedule, and its benefits to whom, the budget and the level of quality to be expected. The executing stage can be seen as a monitoring or controlling stage to be used for control of the overall project and if everything is moving in the right direction on time and on budget. Perhaps this stage can be surpassed for some projects if during the other stages, there is still some level of monitoring and controlling taking place. The delivery stage involves delivering the project product to the customer and redeploying project resources. This may include customer training, transferring documents, releasing materials to other projects or finding new assignments for personnel.
Gray, C.F.; Larson, E.W. (2008). Project management: The managerial process, 4th Ed.
New York, NY: McGraw-Hill/Irwin.