A New Schedule Estimation Technique for Construction Projects

Abstract

Allen studied hundreds of construction projects and developed an accu-rate, practically useful model of their labor profiles. We combine Al-len's labor profile with standard Earned Value Management (EVM) techniques and derive a simple, practical formula that estimates the fi-nal schedule from early project data. The schedule estimation formula is exact; it requires no approximations. The esti-mate is also surprisingly accurate and available early enough in the project for the project manager to be able to take appropriate actions. We use one of Allen's real-world construction data sets to calibrate and validate our theoreti-cal model. Early estimates of the final schedule are remarkably accu-rate, and available early enough to be used to effect management changes. We also explain why a current schedule estima-tion method, Earned Schedule (ES), has a poor theoretical foundation and show that our model is superior to ES in predicting construction schedule delays. The model should provide warning of schedule delays early enough for project managers to take corrective actions.