Semnan University Press Journal of Modeling in Engineering 2008-4854 17 58 2019 09 23 Scheduling of jobs and maintenance activities in an unrelated parallel machines environment Scheduling of jobs and maintenance activities in an unrelated parallel machines environment 233 247 4014 10.22075/jme.2019.14959.1483 FA Abed Hesam Department of Industrial Engineering, Mazandaran Institute of Technology, Babol, Iran Saeed Emami Department of Industrial Engineering, Babol Noshiravani University of Technology Ramezan Nemati Keshteli Department of Industrial Engineering, Babol Noshirvani University of Technology Journal Article 2018 06 09 Scheduling of jobs and maintenance activities is a vital problem in a production system. In the current business environment, the competitiveness of manufacturing companies is based on their ability to response the rapid changes in demand with high quality and low costs. Therefore. in this paper, the Scheduling of jobs and maintenance activities in an unrelated parallel machines environment is studied. By considering the controllable processing times, a multi-objective mathematical programming model is presented to minimize the sum of the compression and expansion of processing times and maintenance costs, makespan, tardiness, and earliness. The multi-choice goal programming (MCGP) is applied. The problem is NP-hard, therefore, the NSGA-II algorithm is developed to solve the medium and large size instances. The obtained results from solving the proposed model with NSGA-II and comparing with the results from MCGP demonstrates that the proposed algorithm is presented a non-dominated solution set in a short time. Scheduling of jobs and maintenance activities is a vital problem in a production system. In the current business environment, the competitiveness of manufacturing companies is based on their ability to response the rapid changes in demand with high quality and low costs. Therefore. in this paper, the Scheduling of jobs and maintenance activities in an unrelated parallel machines environment is studied. By considering the controllable processing times, a multi-objective mathematical programming model is presented to minimize the sum of the compression and expansion of processing times and maintenance costs, makespan, tardiness, and earliness. The multi-choice goal programming (MCGP) is applied. The problem is NP-hard, therefore, the NSGA-II algorithm is developed to solve the medium and large size instances. The obtained results from solving the proposed model with NSGA-II and comparing with the results from MCGP demonstrates that the proposed algorithm is presented a non-dominated solution set in a short time. https://modelling.semnan.ac.ir/article_4014_1cdf14d1e3699d61d237cf76ce1c2dca.pdf