Scheduled Overtime and Labor Productivity: Quantitative Analysis

Abstract

This paper describes a study of 121 weeks of labor productivity data from four industrial projects. The objective is to quantify the effects of scheduled overtime. First, it describes how the data were collected, processed, and analyzed. The results show losses of efficiency of 10–15% for 50and 60-h work weeks. The results compare favorably to other published data including the Business Roundtable (BRT) curves. Therefore, it was concluded that the BRT curve is a reasonable estimate of losses that may occur on average industrial projects. Second, this paper addresses the reasons for efficiency losses. For this analysis disruptions in three categories—resource deficiencies, rework, and management deficiencies—were analyzed. The analyses showed that the disruption frequency, which is the number of disruptions per 100 work hours, worsened as more days per week were worked. This led to the conclusion that losses of efficiency are caused by the inability to provide materials, tools, equipment, and information at an accelerated rate.