FIGURE 22-4. Build a tower project with dedicated effort (no padding).

Figure 22-5 shows the project after resources are leveled.

The next step is to identify the Critical Chain—the longest chain of dependent events, where the dependency is either task or resource related. Looking at Figure 22-5, we can identify several possible paths. In considering which path is the most critical, Critical Chain looks at two possible paths for every task.

One path asks, "What is the next task that is logically dependent on this task?" For example, after the second task, "Purchase Raw Materials" in Figure 22-5, the next task that is logically dependent on purchasing raw materials is task 3, Fabricating the Poles and Base. You cannot fabricate without purchasing.

Another path asks, "What is the next task that uses the same resource as the current task where the dependency is therefore a resource dependency?" In the above example, after "Purchase raw materials," which uses the Procurement resource, the next task using Procurement is "Purchase available Parts."

Based on this analysis, Critical Chain examines the duration of each of the possible paths and picks out the longest path based on task or resource dependency. In this example, Figure 22-6 identifies the Critical Chain, shown in shaded format.

To finish the Critical Chain schedule, the project and feeding buffers must be inserted. Buffers are illustrated in Figure 22-7 with bold text. The buffers were calculated at 40 percent of the length of the paths.

Every task is now attached either to a feeding buffer or to the project buffer. In this example, there are three paths that feed into the Critical Chain. Therefore, there are three feeding buffers. The task "Design Custom Parts" feeds the Critical Chain directly and also feeds another task, "Original Drawings" on a feeding path.

With the protection now accumulated, the effect of individual task time deviations during execution are insulated by the buffers. In effect, the buffers act as shock absorbers.

Project Management Made Easy

Project Management Made Easy

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.

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