Research On Inventory-routing Problem In Reverse Logistics System Of Reusable Packages

Facing with the serious state of resources and evergrowing fierce market competition, all enterprises hammer at establishing a kind of environmental-friendly business operation mode based on theory of circular economy. The trend is widely supported by legal provisions and the public. What’s more, it’s also an important mean for the enterprise to cost reduction and image building in customers. Because of this, the theory of reverse logistics attracts great attention of academic and business circles in recent years. And the package recycle reverse logistics shows great potential in operation optimization, however it is often overlooked that could have played an important role in business operation cost saving.As we all know, vehicle routing optimization and inventory control decisions are two key components of logistics system optimization problem. And we must pay more attention to the inherent relevance between these two parts when carrying research. The joint optimization of vehicle routing and inventory control is called Inventory routing problem which is short for IRP. IRP is designed to balance the inventory cost and vehicle transportation cost and optimize logistics system as a whole by the means of various optimization methods. Packages act a vital role in the link of producing and sale. And based on the characteristics of packages, the reverse logistics system can be set up on a foundation of forward logistics network. The optimal management of package recycle logistics will make a contribution to cutting the cost of package management, perfecting customer service and improving the market competitiveness. Meanwhile, it’s an attitude of taking social responsibility actively.This article takes the package recycle logistics network as the foundation, analysis the particularity of recycling logistics system and study the package IRP in recycle reverse logistics system. In recycling logistics system, packages collected from recycle and achieved from purchasing usually have homogeneity in most instances, and recycling ones can be used for the inventory supplement directly, so that the inventory control for package is generally faced with Dual-source supplement. According to the characteristics above, this paper established a nonlinear integer programming model, which is used to describe dynamic inventory routing problem in the reuse reverse logistics system of package with multiple distribution centers. The purpose is to provide decision-making scheme of recycling path selection and inventory control. This model takes the vehicle load limit and time windows of serve customer point into account to give punishment to advance or delay service. And the objective function is to minimize the total cost of reverse logistics system, including recycling tour cost of vehicles, storage cost of available packages and cost of new packages procurement.IRP is classed as NP-hard problem, so this article chooses genetic algorithm to solve the model, and optimizes the selection method of initial population and genetic operators to improve the efficiency of genetic algorithm. Finally, an example of recycling pallets in an auto parts manufacturing enterprise is proposed to verify the rationality and feasibility of the model and algorithm.