Modified But-For Method for Delay Analysis

“But-for” is a widely used method for analyzing and apportioning project delays among the responsible parties. Despite its acceptability, the traditional but-for method suffers from serious drawbacks; namely its narrow focus on the point of view of a single party and its inability to accurately consider concurrent delays. In this technical note, several improvements have been made to the but-for method to produce repeatable results and to account for concurrent delays. Details of the modified but-for (MBF) method are provided along with an example to demonstrate its advantages. To automate the MBF method, it has been coded in a macro program on commercial project management software. The method is simple and can help practitioners in apportioning project delays in an accurate and equitable manner.