Both the Critical Chain Method (CCM) and the Critical Path Method (CPM) are project management strategies that strive to identify and prioritize the tasks that are critical to the timely completion of a project.
The critical path method (CPM) is a project management strategy for identifying a project’s critical path, which is the sequence of tasks that must be done on time for the project to be completed on time. The critical path is determined by identifying the activities with the longest durations in the project and their dependencies. Project managers may ensure that the project stays on track and is completed on time by focusing on the key path.
The critical chain approach is a variant of the critical path method that takes into consideration the fact that many projects have shared resources (e.g., staff and equipment). It also considers the reality that many jobs are not completed exactly as intended, which might affect the entire project schedule. The critical chain approach involves identifying the critical path in the same way that the critical path method does, but it additionally includes time buffers to account for resource contention and task uncertainty. The critical chain method seeks to lessen the risk of project delays by including these buffers.
There are, however, some significant distinctions between the two approaches:
- Focus: CCM is concerned with managing limited resources, whereas CPM is concerned with managing the sequence of operations.
- Schedule creation: In CCM, the schedule is created by first identifying the project’s critical chain (the longest chain of dependent activities) and then adding buffers (extra time) to accommodate for uncertainties and anticipated delays. The schedule in CPM is created by first determining the critical route (the longest sequence of dependent activities) and then calculating the length of each activity.
- Safety margins: The CCM schedule incorporates buffers to accommodate for uncertainties, but the CPM schedule does not.
- Resource levelling: CCM employs resource levelling to ensure that resources are used efficiently and that wasted effort is minimised. CPM makes no mention of resource levelling.
Overall, CCM is a more comprehensive project management technique that considers both the sequencing of activities and the availability of resources. CPM is more concerned with the sequence of activities and is frequently used in tandem with other project management strategies.
