schedule definition and layout
During this first stage you design the schedule. This design requires a thorough understanding of the scope of the project, an identification of the major constraints imposed by the contract, and conversations with all major subcontractors. Understanding the scope of the project will identify the major types of work to be performed and work areas through which crews move through as they complete the work. Project constraints such as required finish date, phasing, and site access controls will also require modeling within the schedule. Discussing how the work is to be accomplished will allow a realistic picture of how the work is to be accomplished and the expected duration and value of each task.
Some prime contractors contract out the production of CPM schedules to consultants without providing sufficient resources to ensure that the schedule is actually coordinated with those who are to perform the construction. The schedule, in this case, is essentially a spreadsheet that is only used as a table of values to justify progress payments. While there is a value to using CPM as a schedule of earned value, use of a schedule for only progress payment will result in an inability to use the schedule to evaluate the impact of delays or changes.