project buffer

The determination of the critical path of a project requires forward and backward calculation steps (see “Scheduling projects: How to determine the critical path using activity slack calculations?”) and allows for the calculation of three different slack values. In this article, the following three definitions of activity slack will be discussed:

• Total slack
• Safety slack
• Free slack

The Critical Chain/Buffer Management (CC/BM) approach aims at the construction of latest start schedules where the project activities use aggressive time estimates and puts a clear focus on the determination of a realistic project deadline. In order to keep the probability high that the project deadline will be met, the CC/BM approach protects the project duration and the critical chain of the project using various buffers. This buffered scheduling approach is the topic of this article and is discussed along the following dimensions: