Enhanced but-for method to apportion net delays and accelerations

The but-for analysis and its improved modifications have been proposed in the literature to provide a systematic methodology to analyze project delays and accordingly determine the parties' contribution in a manner that does not depend on any party's viewpoint. These methods, however, only apportion net project delays, overlooking net project accelerations that can be owner requested or voluntarily done by the contractor. This technical note thus aims at extending the but-for computations to apportion net schedule accelerations. The proposed enhanced but-for method (EBFM) uses Venn diagrams and set theorem to represent all concurrent delays/accelerations that are shared among the three project parties: owner, contractor, and third party. Accordingly, a mathematical formulation has been proposed to compute each party's contribution to net project delays and/or accelerations. A case study is used to demonstrate the EBFM method and prove its usefulness to both researchers and practitioners. EBFM offers a computational approach to help prepare and settle claim disputes in a fair and repeatable way, considering a variety of project conditions that include delays and accelerations.