Mixed-Integer Linear Programming on Work-Rest Schedule Design for Construction Sites in Hot Weather

An appropriate design of work-rest schedule is recognized as an efficient way in providing better ergonomic environment, improving labor productivity as well as safety. Construction workers usually undertake physically demanding tasks in an outdoor environment, with awkward postures and repetitive motions. This study proposes a mixed-integer linear programming approach to optimize the work-rest schedule for construction workers in hot weather for the objective of maximizing the total productive time. The model takes into consideration the physical and physiological conditions of the workers, the working environment, the nature of the jobs and the minimum rest duration of the government regulation. The results of numerical experiments show that the proposed model outperforms a default work-rest schedule by up to 10% in terms of total productive time. This implies considerable cost savings for the construction industry.