Enhanced Iterated local search for the technician routing and scheduling problem

Most public facilities in the European countries, including France, Germany, and United Kingdom, were built during reconstruction projects between 1950 1980. Owing to deteriorating state of such vital infrastructure, its maintenance has become relatively expensive recent decades. A significant part operation costs is spent on technical staff. Therefore, optimal use available workforce essential minimize overall costs. This includes planning interventions, workload balancing, productivity improvement, etc. In this paper, we focus routing technicians scheduling their tasks. We address for purpose a variant problem called Technician Routing Scheduling Problem. applications different fields, as transportation infrastructure (rail road networks), telecommunications, sewage facilities. To solve problem, propose an enhanced iterated local search approach. The enhancement firstly intensification procedure that incorporates set operators removal-repair heuristics adapted studied problem. Next, four mechanisms are used perturbation phase. Finally, elite solutions extensively explore neighborhood optima well enhance diversification space exploration. measure performance proposed method, experiments conducted based benchmark instances from literature, results obtained compared with those existing method. Our method achieved very good results, since it reached best gap, which almost three times lower than literature. Furthermore, eILS improved best-known solution 31 among total 56 while maintaining reasonable computational times.