An Integrated Critical Path Method and PERT Approach for Schedule Performance Evaluation of Drainage Construction Projects

Abstract

Time control is a critical factor in the successful delivery of urban drainage construction projects, which are often characterized by high complexity, limited working space, and uncertain site conditions. Delays in such projects can have significant economic and social impacts, underscoring the need for reliable methods to evaluate schedule performance, particularly when detailed activity-level data are unavailable. This study aims to evaluate the schedule performance of a drainage construction project by integrating the Critical Path Method and the Program Evaluation and Review Technique, using an aggregated schedule derived from the Work Breakdown Structure. The methodology involves developing a network model to identify the dominant activity sequence that determines project duration, followed by probabilistic analysis to assess uncertainty in critical work packages. The results indicate that the dominant path consists of preparation works, earthworks and piling works, drainage channel construction, and pedestrian access works, with the latter two activities exerting the greatest influence on project completion. The analysis further reveals that uncertainty in key activities, particularly drainage channel construction, reduces the likelihood of completing the project within the planned 180 calendar days if not properly controlled. The study concludes that integrating deterministic and probabilistic scheduling approaches provides a more comprehensive and realistic evaluation of schedule performance. This approach is especially useful for infrastructure projects with limited data availability and offers practical support for improving project time control and managerial decision-making.