The supply of convenience stores: Challenges of short-distance routing within the constraints of working time regulations

Convenience stores are small shops typically located in dense urban areas. They are an important element in modern retailing considering growing urbanization. The layout of convenience stores usually differs significantly for individual stores depending on the local conditions and the types of store (e.g., grocery stores, kiosks, gas stations). Convenience stores have specific delivery requirements that differ significantly due to their variety. In this context, retailers have to cope with small order sizes and frequent deliveries that need to occur within opening hours or predetermined time windows. In addition to these requirements, working hour regulations for the drivers, i.e., the consideration of break times and tour duration restrictions, have to be respected. These regulations have so far been neglected within short -distance routing but significantly impact the planning in practice. The supply of convenience stores is thus a major challenge for retailers. This article addresses the supply of convenience stores as it takes place at a major European retailer. We develop a mathematical model that integrates existing working time regulations and actual requirements in retail practice. The resulting routing problem is solved using an adaptive large neighborhood search. We demonstrate the impact of the requirements imposed on the routing problem and corresponding delivery solutions in numerical studies. Our experiments show that ignoring break times within route planning when strict time windows are given leads to non -feasible solutions and a potential delay in deliveries of more than 18 h for a single planning week.