Concepts and Methods of Schedule Compression
It is control of project time, along with cost and quality, that comprise the basic goals for project management. How important is time? The phrase, “time is of the essence,” is often found in the contract documents of owners, and is intended as a strong reminder to the engineer and/or constructor that the time milestones in the project have economic significance for the owner and that control of time is expected. Time control is important for the contractor as well, however, since time savings can improve profits and loss of time is costly.
Both proactive and reactive aspects to time management can be found. The proactive aspects are part of planning-how should the project stakeholders organize their efforts to reduce the time required to achieve the engineering and construction objectives? Every planner must constantly challenge historical schedule performance on similar work with the objective of reducing time without sacrificing other project objectives. These proactive efforts will yield the greatest return.
The reactive aspects of time management occur during the execution stage, when negative time variances threaten or begin to appear and actions must be taken to overcome those variances. How do the stakeholders best assure that time will not be lost needlessly? In both the proactive and reactive modes, the managers are seeking ways to achieve schedule compression. Thus, a knowledge of schedule compression techniques should be part of the skills and knowledge base of the professional project manager.
In 1986, the CII Cost/Schedule Task Force, through Colorado State University, undertook a study of schedule compression. The objectives of the study were to identify and evaluate schedule compression techniques that can be considered in one or more of the engineering, procurement, and construction phases of a project. Following many interviews with experienced engineering and construction personnel, a catalog of schedule compression techniques was compiled. During subsequent discussions within the Cost/Schedule Task Force, the original list was refined and a number of additional techniques added. This publication summarizes the results of those efforts. Readers are encouraged to obtain the source document (SD-55) for further details.
As will be obvious from reviewing the techniques provided, some could be classified as techniques of constructability, productivity improvement, materials management, or some other management function. This should not be unexpected. As one studies the individual components of effective project management, it becomes apparent that the many functions included within the total are overlapping and interdependent. Thus, it really is not important which function claims credit for an idea or technique for improving cost, time, or quality management; it is only important that this idea be made known to those who can find value in its application. In addition, there is advantage to repetition: An idea, if seen and heard often enough, soon becomes ingrained as accepted practice.
As used in this publication, “schedule compression” refers to the shortening of the required time for accomplishing one or more engineering, procurement, construction, or startup tasks (or a total project), to serve one of three purposes: (1) reducing total design-construct time from that considered normal; (2) accelerating a schedule for owner convenience; and (3) recovering lost time after falling behind schedule. As will be seen in the subsequent discussion, some schedule compression is forced, but much is achieved simply by preventing needless loss of time.
