What is a Critical Chain?
Critical chain is another schedule network analysis technique that modifies the project schedule to account for limited resources. The critical chain combines deterministic and probabilistic approaches.
What is the Critical Chain Method?
The Critical Chain Method (CCM) is a project management process. The CCM method helps project managers determine which activities are critical for the completion of the project in order to effectively allocate the time required for each task. This information then guides their work assignments.
The idea behind this method of project management is to create a detailed list of each task in a project. This list is then broken down into segments. Each segment is a day and these days are ordered to find the longest continuous piece of work on a project. From there, it is possible to measure the progress of the project.
Initially, the project schedule network diagram is built using non-conservative estimates for activity durations within the schedule model, with required dependencies and defined constraints as inputs. The critical path is then calculated. After the critical path is known, resource availability is entered, and the resource-limited schedule result is determined. The resulting schedule often has an altered critical path.
The critical chain method adds duration buffers that are non-work schedule activities to maintain focus on the planned activity durations. Once the buffer schedule activities are determined, the planned activities are scheduled to their latest possible planned start and finish dates.
Consequently, instead of managing the total float of network paths, the critical chain method focuses on managing the buffer activity durations and the resources applied to planned schedule activities.
Consequently, instead of managing the total float of network paths, the critical chain method focuses on managing the buffer activity durations and the resources applied to planned schedule activities. A study by researchers at George Washington University found that telecommunication companies who successfully implemented the critical chain method realized 18% greater productivity with 22% less overtime hours worked; they also cut inventory costs by 25%.