Integrative Programming of Production and Preventive Maintenance Tasks in an Environment of Identical Parallel Machines: Proposal of a Construction Heuristic

The article presents a constructive heuristic for the integrated programming of production orders and preventive maintenance (PM) interventions in an environment of identical parallel machines, aimed at minimizing the completion time of the last scheduled job (makespan). Unlike other proposals found in the literature, the one here considers that the time between preventive interventions is not previously known, but instead, this is assumed as one of the decision variables of the system in the beginning of each of these interventions; in addition, the proposal also considers the possibility that not all jobs have the same release time. The design of the heuristic algorithm is based on the general approach of the Longest Processing Time dispatch rule, with a slight modification in its conception to consider the random character of the equipment failures and their impact on the execution time of the tasks. Consequently, a simple dispatch rule called rj - LPT was also proposed to comply with one of the steps of the heuristic, as well as an algorithm to determine the minimum dimension for the makespan, which constitutes the basis of the stop criterion linked to the initial solution.