Theory of Constraints Handbook - James Cox Iii [39]
The practitioners have voiced the strongest criticisms of current project management methods. This is because the current reward systems are based not upon the method used but upon the results received—on time, on budget, and to full specifications. Recognizing the inadequacies of PERT-based methods in achieving the desired results, practitioners attempt to modify these project management methods.
Practitioners recognize the effects of variability and finite capacity when their projects are completed late and over-budget, but do not understand the underlying reasons for the observed effects. They intuitively “know” that PERT/CPM assumptions are causing their project to fail, but have not recognized that their own behavior is also a cause. These behaviors, such as project managers seeking to delay spending or to avoid late penalties, or resource managers increasing planned activity duration to protect their resources, are driven by policies and measures. (A full discussion of policies and measures, how they influence behavior, and how to align individual behaviors with corporate goals is far beyond the scope of this chapter.)
Important recommendations to practitioners may be made because of the research presented in this chapter. Project managers should understand that estimates of activity duration are prone to over-estimation and, counter-intuitively, often lead to poor project performance. Project managers should also understand that multiple projects are interdependent due to the shared use of common resources. As such, decisions made with respect to one project may have detrimental effects on other projects, even projects that have not yet started. Additionally, a reward system should be developed that recognizes the completion rather than the duration of both activities and projects. Resource managers need to understand the concept of a Critical Chain and must also take advantage of early activity completions. Finally, project managers should not base planned project completion dates on PERT-based plans, but rather on some method that recognizes the shared use of common resources and the existence of statistical fluctuation within and across projects.
Researchers have identified many of these surface problems in their studies; however, no comprehensive examination of the causes of these surface problems has been undertaken. We feel this approach is not enough. To provide a practical framework for reducing project failures, a systems approach must be taken to identify both macro and micro surface problems, core drivers (environmental factors), and core problems with the PERT/CPM methodology. We do not propose a comprehensive solution to addressing project management; however, we do provide some guidelines to start a dialog with other researchers in developing a more effective and practitioner-friendly approach to project management. Researchers should use these guidelines as a starting point to develop algorithms that are more robust. Goldratt’s Critical Chain method offers promise in addressing many of these problems. It has been used effectively in a limited but growing number of different environments. That method and others need to be developed and refined to provide a systems perspective encompassing the needs of project managers, resource managers, and organization managers.
Policies, procedures, measures, planning, and control methods need to be re-examined as indicated by the current reality trees of single and multiple project organizations. Underlying conflicts among the goals and measures of managers create many of the surface problems seen in a project management environment. These conflicts must be resolved by providing supporting policies, procedures, and measures. Given that these can be devised and successfully implemented, a systems perspective must be utilized to identify all of the core drivers in a given environment and the planning and control system so structured to accommodate these core drivers. The project environment has several common core drivers that must be incorporated