Impact of Overtime Work on Construction Labor Productivity: Evidence from Work Sampling Analysis of Finishing Activities

Abstract

Construction projects frequently encounter field constraints that affect cost, schedule, and quality performance. When delays arise, contractors often adopt overtime work as an acceleration strategy using the existing workforce. However, such practices may lead to concerns regarding productivity decline. This study investigates the impact of overtime work on construction labor productivity based on the Five-Minute Rating method, focusing on plastering and skim coating activities in a residential project in Palangka Raya, Indonesia. A systematic work sampling approach was employed, comprising 1,296 observations collected over six days, with comparisons made between regular working hours and overtime periods. The results indicate distinct productivity responses across work types. Plastering exhibited only a marginal reduction in Labor Utilization Rate (LUR) of approximately 1%, whereas skim coating showed a more pronounced decline of about 6.5% during overtime. Effective activities decreased by approximately 6% under overtime conditions. In contrast, volume-based analysis suggests that output increased during overtime, with gains of 28% for plastering and 49% for skim coating. Statistical analysis suggested a significant difference in productivity for skim coating (p = 0.031), while no statistically meaningful difference was observed for plastering (p = 0.109) at the 95% confidence level. Despite the observed increase in output, the achieved productivity levels remain below standard unit price analysis benchmarks.