Improved baseline method to calculate lost construction productivity

The measured mile/baseline method has been widely accepted to quantify labor productivity loss, which is demonstrated by comparing the impacted and unimpacted/lightly impacted portions of the work. Although the distinctions between these portions of a project can at times be identified through a cause and effect analysis, on many projects this distinction is not readily observable. For those projects, researchers and professionals have developed various procedures to implement the measured mile/baseline calculations, but shortcomings in those procedures can result in the failure to objectively identify the baseline. In this paper, a method based on basic statistical techniques is proposed to determine a baseline that represents the contractor's normal operating performance, thus overcoming many of weaknesses in the existing methods. This paper will provide construction professionals and engineers with an objective approach to determine the productivity baseline, thus aiding in the resolution of labor productivity loss claims. Further, this new method avoids the arbitrary baseline sample size and the possibility of multiple competing solutions in existing methods. A numerical example is included to compare the results using different methods and demonstrate the advantages of the proposed method.