Whether the schedule is prepared intuitively or scientifically, the scheduler must understand how the various materials, trades, equipment, and subcontractors combine to produce a completed project. Developing this schedule is not merely a mechanical exercise. Many judgments must be made, and the schedule's reliability depends largely on their quality. Personnel making such judgments must have a thorough knowledge of the job site conditions, the contractor capabilities and methods of operations, the CPM scheduling system, and the contractual liability of the participants. Understanding how the various materials, trades, and subcontractors combine to produce a completed project is an ability acquired after years of study, observation, and experience.
Scheduling is truly an output of the planning process, which is an art.
The quality of the exercise is thus a function of the ability of the scheduler to combine creativity with experience in order to develop a product that meets the needs of the project and thus the client's objectives. Scheduling is done by people, not computers. Computers may assist the planner and the scheduler by sorting, storing, performing math, and matching data, but they do not provide the intellectual direction and creative thought required to produce a schedule for a unique, complex construction project. The scheduler must pull together data from the various individuals and organizations that form the project team, refine these data, remove bias, and develop a comprehensive and coordinated plan represented as a schedule. The scheduler must have the basic mechanical scheduling skills as a minimum.