The multi-shift single-vehicle routing problem under fuzzy uncertainty

In this paper, we study the single-vehicle routing problem (VRP) with time windows, multi-shift, and fuzzy uncertainty. In this problem, one vehicle is used repeatedly to serve demand over a planning horizon of several days. The problem is inspired by a routing problem in maintenance activities, where one maintenance crew uses a vehicle to perform jobs in various locations. Crew operates in shifts and always returns to depot before shift ends (no overtime is allowed). The objective consists in completing all the maintenance jobs in various locations minimizing the number of shifts the crew is used, and reducing the shift duration time. We study the effect of uncertainty in travel and job processing time on KPI. We develop an Artificial Immune Heuristic to solve the addressed problem. A numerical real test study is performed in order to investigate the problem. We propose a framework to evaluate the uncertainty effect. Results show important time saving can be obtained with the proposed approach.