Stochastic-Based Model for Setting Formwork-Productivity Baseline

AbstractSetting the baseline labor productivity (BP) values for construction activities is essential to compare the productivity performances of projects or contractors. The BP value can also be used to estimate the costs incurred due to the loss of productivity on a certain project. The objective of this research is to develop a Monte Carlo simulation-based baseline labor productivity model (MCBPM) that can be used to determine the BP value for formwork operations. After proposing a framework for the MCBPM, empirical data regarding the labor productivity of timber formwork for several building structures were collected from 40 contractors in Ethiopia. Thereafter, a Monte Carlo simulation was carried out to simulate the formwork labor productivity, and BP values were set. Following the simulation, the BP values for column, beam, slab, and wall formworks, at 95% probability, were found to be 0.94, 0.80, 0.93, and 1.0 m2/h, respectively. Compared to the previous BP models, the MCBPM provides more reliable estimation accuracy and efficiency to set the BP value based on the confidence level. This study contributes to the body of knowledge by proposing a stochastic labor productivity model that can be used as a practical tool in construction projects to forecast the BP values at certain confidence levels.