Developing a novel framework to manage schedule contingency using theory of constraints and earned schedule method

In this paper, a novel framework is presented for estimating, allocating, and managing schedule contingency using the theory of constraints and the earned schedule technique. The main aim of the proposed framework is to present a practical technique to manage schedule contingency in a manner that is easy to use and simple to understand; can overcome the drawbacks of earned value management for the schedule component; can overcome the inaccuracy caused by using critical path method; and takes into account the statistical nature of each activity and merges them to form a single framework. The framework introduces two new measures, buffer performance index and buffer variance, for measuring the expected remaining buffer and the actual remaining buffer on critical and noncritical chains based on the percentage completion for each activity at the end of the reporting period, respectively. To verify the proposed framework, the processes and measures have been applied to three projects, each with different complexities. The results show potential for managing buffers when placed at the project level, without the involvement of complex mathematical models or tedious equations.