Critical Chain Method in Project Management

Project management demands efficient scheduling and resource allocation in order to reach successful project completion.

One method designed to address these challenges is the Critical Chain Method based on the Theory of Constraints (TOC). This technique focuses on optimizing project schedules and resource usage while increasing project performance.

In this article we’ll dive deeper into its principles and steps, showing how it can improve the performance of any given project.

What is the Critical Chain Method?

The Critical Chain refers to a sequence of tasks which determine the overall project duration, taking into account task dependencies, resource availability and uncertainties. Determining its position requires studying your network diagram in detail and finding its longest path from start to finish; when properly leveraged project managers can effectively control timelines while eliminating bottlenecks from their projects.

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%.