A Multiobjective Approach to the Problem of Task Sequencing and Tool Changing on Non-Identical Parallel Machines

Flexible Manufacturing Systems often operate with tool holders of limited capacity, which requires tool changes between consecutive tasks. In environments with non-identical parallel machines, capacity differences, machine-dependent processing times, and changeover times make sequencing decisions strongly interdependent. Previous studies on this formulation of the problem address in isolation objectives such as tool changes (TS), makespan (Cmax) and total flow time (TFT). This work investigates a multiobjective approach based on Iterated Local Search, called MO-ILS, simultaneously considering the objectives (TS, Cmax). Computational experiments were carried out to compare the proposed methodology with an exact technique.