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FIGURE 3-12 Critical Chain implementation empowerment model. (Adapted from Budd & Budd, 2010, 260.)
Step 1 in Fig. 3-12 establishes the motivation for change (Why change?). A critical mass of individuals must recognize the pain resulting from continued use of the current system—in this case, traditional project management. Step 2 is the TOC first layer of resistance.34 The remaining steps proceed in numerical sequence. All of the steps must be addressed and none skipped. Some have to be visited more than once if some members have been left behind at another step or now question a previous step.
The dotted line from Step 8, “Evaluate results of CCPM to assess value to the organization,” to Step 5, “Ensure that all significant unintended consequences of CCPM have been surfaced and addressed,” indicates that Steps 5, 6, 7, and 8 may have to be repeated multiple times as implementation proceeds and negative unintended consequences are experienced and overcome.
Once all 10 steps have been taken, a CCPM system is in place and, if no steps have been passed too quickly, the system is working and benefitting the organization as planned. However, as the environment changes, new practices may develop that require changes in the installed system. Therefore, a dotted line also extends from Step 10, “CCPM is established as best practice and standard operating procedure,” back to Step 1, signifying the need for a significantly revised project management system. Of course, new improvements in CCPM are being developed every day (see the next three chapters in this book), and your system should be revised from time to time, which may require only a portion of the 10 steps.
Summary
This chapter presents a basic approach to CCPM concepts. Because task times have skewed distributions and cannot be predicted accurately, CC is designed to avoid the dysfunctional behaviors of ineffective multitasking, the student syndrome, sandbagging, and the impact of Parkinson’s Law typical in traditional project management.
To shift concentration from local optima to global optima, safety time is removed from individual tasks and used to protect the entire project. Resource contention is addressed early in the CC planning process and time buffers are used to address task time uncertainty. Communication tools called resource buffers add to the project communication process and scheduling buffers control the initiation of new projects into the multi-project mix. Full kitting is completed prior to the release of a project. The chapter describes the six regular steps and one optional step in scheduling a single CC project. The three primary sources of safety for on-time project completion are the project buffer, multiple feeding buffers, and multiple resource buffers.
In multi-project environments, it is essential to have a prioritizing process for projects. None of the projects will complete on time if there are so many projects that resource scheduling is difficult and multitasking is rampant. A “Wafer Experiment” located at www.mhprofessional. com/TOCHandbook is an excellent way to experience the effects of bad multitasking. A SR is similar to the constraint resource in DBR implementations in manufacturing. A scheduling buffer, based on the SR’s availability, will minimize resource conflicts and prevent choking the organization with too many projects.
Buffer Management gives the PM important information on the project status. When actual task durations are longer than planned in the project schedule, the overages are subtracted from the buffer. Normal variations in task durations are expected to consume some or all of the buffer time during the operation of the project. An extreme rate of buffer consumption can inform the PM when extraordinary action is required. As the project is completing, the size of the buffers can be reduced as there will be less and less task protection time required.
The use of time buffers in the project schedule has been covered extensively and