Schedule delays of major projects: what should we do about it?

Cost overruns and schedule delays are one of the most common reasons for project failure. Although schedule delays not only result in significant financial implications to project sponsors but also lead to substantial social costs to the public, scant attention has been dedicated to schedule delays [Padalkar, M., & Gopinath, S. (2016). Six decades of project management research: Thematic trends and future opportunities. International Journal of Project Management, 34(7), 1305-1321]. This study therefore investigates the frequency, magnitude, and characteristics of schedule delays occurring during the construction of 113 large public procurements built in the U.S. and the U.K. between 1999 and 2018. Through tests of hypotheses, this study finds that there is a gap between presumptions and reality. Although extensive efforts were made to project controls in the U.S. and the U.K. over the last two decades, this study also finds that project performance has not improved at all from a schedule perspective. In order to address the issue, this study then suggests reference class forecasting to develop more realistic and reliable schedule estimates.

Automated summary

Cost overruns and schedule delays are common reasons for project failure. Despite efforts in project controls in the U.S. and U.K. over the last two decades, project performance has not improved from a schedule perspective. The study suggests using reference class forecasting for more realistic and reliable schedule estimates.