In this paper, a new variant of the well-known vehicle routing problem with time windows (VRPTW) called as the simultaneous product and service delivery problem with order release dates is studied. The problem is motivated by the operations of a 3PL service provider who manages the last mile delivery of electrical and electronic home appliances of a large retailing company based out of China. Apart from the usual constraints on time windows and vehicle capacities, an interesting characteristic of this problem is that the product and service delivery has to happen simultaneously with the explicit consideration of order release dates. This situation necessitates the presence of a skilled service technician at the time of product delivery itself. Being a proven NP-hard problem, we propose a mixed-integer linear programming (MILP) formulation for the problem. For solving large problem instances, an adaptive large neighborhood search (ALNS) algorithm is developed with three new customized removal operators. The proposed approaches are validated using real-life data as well as benchmark problem instances available in the literature. The computational results are quite encouraging and demonstrate the superior performance of the proposed algorithm in terms of computational time as well as the quality of the solutions generated. We also analyze the effect of length of time windows and compare simultaneous and separate modes of delivery and identify favorable conditions for choosing one mode over the other.
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