Multiperiod integrated spare parts and tour planning for on-site maintenance activities with stochastic repair requests

Motivated by the problem facing many home-attended maintenance service providers, this paper considers the joint optimization problem of spare parts planning and the scheduling of a single technician to visit geographically distributed customers for on-site maintenance activities. We present and formulate the problem using stochastic mixed-integer programs, encompassing many important real-life characteristics, such as stochastic spare parts demand, stochastic customer requests, and return visits. We also propose an anticipatory solution method, which uses a look-ahead procedure to integrate stochastic information into the planning process and compare this with two myopic planning approaches. With a detailed numerical study, we show that anticipation can lead to cost reductions and service level improvements, especially when customers are sparely distributed. Furthermore, our results reveal that the repair kit and technician tour integrated planning helps to substantially reduce penalty costs for late service. We also provide insights into the value of having perfect information about spare part demand and future request locations.