After you review your project plan for overall accuracy and completeness, you fine-tune your schedule even more by making trade-offs among scope, resources, and time — the three main factors that shape a project. In most projects, some of these factors are constrained and some are flexible. For example, if you have a deadline that can’t be missed and you can’t remove tasks to reduce the scope, perhaps you can hire more resources. Or, if you have a limited number of resources, you might be able to reduce the scope.
When you refine your project plan, you focus on shortening the schedule, using resources as efficiently as possible, and reducing project costs. The following sections summarize these objectives, which are covered in more detail in chapters 11 to 13.