Apportioning Concurrent Delays and Accelerations Using Daily Windows
Kehui Zhang, Tarek Hegazy · 2005
Project as-built duration is the resultant of all day-to-day events and actions, including slowdowns, work stops, and accelerations, made by all project parties. In current practice, however, a systematic procedure for recording and analyzing daily actions is lacking, thus making the quantification and analysis of time-related and cost-related claims a complex task that is highly controversial. In this paper, a practical model is presented, with an analytical framework, for analyzing project as-built schedules, considering slowdowns, work stops, and accelerations. The model differentiates between owner-directed and contractor-voluntary accelerations and deals with acceleration as a negative delay attributable to the party that creates it. To provide accurate and repeatable results, the model uses a daily windows analysis technique for apportioning concurrent delays and accelerations. Details of the proposed model are provided along with an example application. The model is readily usable by professionals and researchers to dynamically analyze the impact of all events along project duration.