There are different schedule life cycle types (often called project life cycle). The project manager will choose the best that suits the project requirements. The life cycles are explained below:
Predictive: The entire work is planned and scheduled in the beginning of the project.
Iterative/agile: One or more specific task is planned to be done in periods (iterations) e.g. Three one-week periods. When done, another activity is planned/worked on. This cycle continues.
Adaptive: Same as iterative/agile. However, work is planned in many more and smaller iterations. Hence, there are frequent outcomes coming out from iterations. Adaptive is used in complicated/complex projects.
Rolling Wave Planning: It is iterative planning in which near term work is planned in detail, while the work in future is also planned but at a lower level of detail.
Incremental: Portion of entire work is planned and completed. Then next portion of entire work is planned/completed and this cycle continues.
Hybrid: A combination of approaches for different projects or sub-projects.