Minimizing job tardiness using integrated preventive maintenance planning and production scheduling

Production scheduling and preventive maintenance planning decisions are inter-dependent but most often made independently. Given that maintenance affects available production time and elapsed production time affects the probability of machine failure, this interdependency seems to be overlooked in the literature. We propose an integrated model that simultaneously determines production scheduling and preventive maintenance planning decisions so that the total weighted tardiness of jobs is minimized. We investigate the benefits of integration through a numerical study of small problems. We compare the integrated solution and its performance with the solutions obtained from solving the production scheduling and preventive maintenance planning problems independently. The numerical results show an average reduction of 30% in expected total weighted tardiness. Finally, we discuss the issues related to solving larger problems and extensions for future study.