A decomposition approach for the periodic consistent vehicle routeing problem with an application in the cleaning sector

This study is inspired by a challenging logistic problem encountered in the cleaning service sector. The company wishes to solve the consistent vehicle routing problem over a three-month planning horizon. The company has a heterogeneous vehicle fleet to guarantee multiple frequencies of visits to its customers. The objective is to minimize the number of vehicles used and the total distance traveled. This problem is a generalization of the periodic vehicle routing problem. We decompose the problem into two sub-problems, namely, the planning and routing optimization sub-problems. We construct a mathematical model for the former and a large neighborhood search for the latter. We evaluate the performance of our approach using the results of the industrial partner and instances from the literature on problems that are closely related to our case study. Our approach is found to be effective and robust. Our results outperform the existing company’s plan in terms of solution quality, and staff convenience, and speed. We also discovered new best solutions on some of the instances from the literature.