Rasoul Jamshidi

Many defects in manufacturing system are caused by human resources that show the significance of the human resources in manufacturing systems. Most manufacturers attempt to investigate the human resources in order to improve the work conditions and reduce the human error by providing a proper work-rest schedule. On the other hand, manufacturer deal with machine scheduling based on demand and work type. The mentioned scheduling would be effective if both are simultaneously implemented; then, we confront integrated human- machine systems which work with minimum cost, machine failure and human errors. Considering this fact, we propose a bi-level mixed integer nonlinear model to minimize the machine scheduling costs such as earliness-tardiness cost and interruption cost in the upper level and human error in lower level according to performance shaping factors (PSFs). Several numerical instances are implemented by the proposed model to show the model effectiveness to obtain the best work schedule for human resources and machines in manufacturing systems. © 2018 Materials and Energy Research Center. All rights reserved.

Most manufacturers use human-machine systems to produce high-quality products. Dealing with human-machine systems is very complicated since not only machines should be utilized in proper condition but also appropriate environment should be provided for human resources. Most manufacturers have a maintenance plan for machines but many of them do not have a proper work-rest schedule for human resources. Considering this fact, we emphasis on human role in human-machine systems maintenance and propose a mathematical model that obtains the optimal work-rest schedule for humans based on fatigue-recovery models and the optimal maintenance policy for machines based on reliability level. The performance of proposed model was examined by some instances and the obtained results indicate this model can provide effective maintenance policy for human-machine systems.