Bi-Objective Scheduling Problem on Parallel Machines with Sequence-Dependent Deterioration and Maintenance Operations

Sequencing problems are fundamental in production systems subject to machine deterioration over time. This work proposes a new bi-objective problem of sequencing in parallel unrelated machines, considering sequence-dependent deterioration and the integration of maintenance operations that restore the performance of the machines. The goal is to simultaneously minimize makespan and total task delay. For this, a model of Multiobjective Mixed Integer Nonlinear Programming is formulated. In addition, a new set of instances is generated. For small instances, an enumeration-based method is used to obtain optimal solutions, allowing model validation. The perceptions show that the integration between sequencing and maintenance can improve the performance of the production system, highlighting the relevance of the proposed approach.