Figure 4.1 illustrates the key features of the single-project critical-chain solution that satisfy the functional requirements for the project system. The illustrated features highlight the differences between CCPM and CPM. These essential features are:
1. Identifying the critical chain as the longest path through the project, considering both the task logic and the resource constraint;
2. Removing resource contention from the project plan before selecting the critical chain;
3. Exploiting the plan with mean (~50-50) task estimates, aggregating allowance for common-cause variation and bias into the buffers at the end of task chains (Figure 4.1 illustrates the buffer as a shock absorber);
4. Subordinating merging paths with feeding buffers (while continuing the elimination of resource conflicts);
5. Ensuring resource availability, especially for tasks along the critical chain (the method illustrated identifies resource buffers as one tool for this; I will describe others);
6. Using the project and feeding buffers as measures to control project performance.
The next section describes each of these features in greater detail.
Four essential behavior changes are required to use single-project CCPM effectively:
1. Management must encourage the use of mean task-duration estimates by not pressuring people to perform to the estimated durations.
2. Management must enable people to focus on one task at a time.
3. Resources must focus on one task at a time and pass on the results as soon as the task is complete.
4. Everyone must use the plan and the buffer reports to decide what to work on next.
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What you need to know about… Project Management Made Easy! Project management consists of more than just a large building project and can encompass small projects as well. No matter what the size of your project, you need to have some sort of project management. How you manage your project has everything to do with its outcome.