Assessment of human productivity drivers for construction labor through importance rating and risk mapping

Abstract

Labor constitutes a significant portion of the overall cost of a construction project, where labor productivity is often the main driver of the cost. Although studies on labor productivity factors exist, their frequency of occurrence in terms of their ranking remains unexplored. This study differs from other studies in the literature by introducing the frequency component to the productivity factors, a more realistic ranking of the factors by adjusting the importance by frequency (frequency adjusted importance index) and risk mapping of the factors. Moreover, this study is the first to apply risk mapping on labor productivity drivers. The aim of this paper is to identify the project factors affecting the labor productivity in construction projects and to rank these factors considering the perception of the industry on project performance. A literature review of past relevant studies was performed to identify and draft a list of factors affecting labor productivity in construction projects. Thirty-seven labor productivity factors were presented in a questionnaire to investigate the impact and frequency of their occurrence in construction projects. A 9-point scale structured questionnaire was constructed to measure the importance and the frequency of the factors and to evaluate the ranking for different categories. The frequency adjusted importance index (FAII), Spearman’s rank correlation, and risk mapping were used to study and analyze the 105 completed responses. The participants rated the following factors as the five most significant labor productivity-influencing factors: (1) poor labor supervision, (2) delays in payments, (3) poor work environment, (4) lowly skilled labor, and (5) bad weather conditions.