Schedule acceleration, work flow, and labor productivity

This paper details how construction labor efficiency is affected by deviati ons from the normal how of work. A methodology is presented to estimate the loss of labor efficiency, based on variations in the percentage of labor h ours used each week. The procedure can be used without the need for contrac tor production records. The theoretical basis for the method rests on the a ssumption that the rate of manpower utilization is consistent with the amou nt of work available for the contractor to perform. Using productivity data from three electrical projects that were accelerated, the labor efficiency is shown to be correlated to changes in the percentages of weekly work hou rs. Loss of efficiency curves are developed for various project phases. A c ase study is presented of an actual electrical construction project. Losses of efficiency are calculated for each phase, and it is shown that the cont ractor incurred an estimated loss of productivity of 25%. The analysis is v alidated by comparing a weekly inefficient work-hour profile to the chronol ogy of events that occurred on the project.