Goldratt acknowledges that computer assistance is necessary to calculate the critical chain and to manipulate the various buffers. Here are two products that are available to support CCPM.
The first is ProChain Project Scheduling, from ProChain Solutions, Inc., (703) 490-8821 or www.prochain.com. ProChain sits on top of Microsoft Project, and is run from within MSP. Task Bars and ProChain Views are added to the MSP screen. ProChain will first Load Level, considering dependency and resource constraints. Next, it identifies the critical chain. The next steps create and insert the various buffers. Options are provided to set the parameters for the buffers and to override the automatic placement or computation. A Factor Durations option can be used to set a duration multiplier. For instance, you might want to use the Duration Factor to cut the task durations in half, and then set the buffer options to 50 percent of the path duration. In the brief test that I ran, I had to reduce the durations by about half to compensate for the added duration for all the buffers. Also, in this test, the project duration (after load leveling, but without buffers) was the same as when I invoked MSP's resource leveling function (which I would expect). However, the selected sequence of task execution was different.
If you don't wish to use separate software for CCPM, some of the functions can be achieved via creative use of traditional CPM software that has PERT (three-time-estimate) capabilities. This is available in Scitor's Project Scheduler as well as in MS Project (version 98 and later). Neither of these products will calculate and place buffers, but the PERT analysis can be used to estimate the time that should be allocated for schedule contingency.
Tool Tip Scitor's latest scheduling release, Project Scheduler 8, is the first traditional CPM program to offer support for CCPM as an available option within the basic product. PS8 offers a complete Critical Chain capability as a scheduling option within the basic program. The CCPM capability in PS8 has support for multiproject critical chain scheduling, based on project priorities and constrained by key resources (Drum Resources feature). Scitor can be reached at (408) 745-8300, or at www.scitor.com.
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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.