运力约束下多应急物资供应点选择模型研究

Depot Selection Problems for Multiple Emergency Materials with Transportation Capacity Constraint

考虑供应点运力约束,研究了多应急物资供应点组合选择问题。构建了运力约束下以供应时间最短和供应成本最小为目标的多目标供应点选择模型,提出了将运力约束转化的求解思路,进而利用理想点法求解最优选择策略,最后利用算例验证了解法的可行性。

The depot selection problem for multiple materials has become the key issue related to the collection and allocation of materials in emergency logistics. An effective decision-making process in combination with emergency supply depots can facilitate quick rescue, reduce casualties and property damage, and prevent negative effects. The current literature on emergency materials scheduling problems focuses on the minimization of rescue time without considering cost. In fact, emergency logistics is a multi-objective system and it is necessary to consider the rescue cost for maintaining sustainable rescue capabilities. This article argues that the emergency supply depots selection is an issue that needs to address multiple objectives with the constraints of the diversity of emergency materials and transportation capacity. This article investigates the selection problem of multiple supply depots for multiple materials emergency logistics. It constructs a multi-objective model with capacity constraints in which the objectives are the shortest supply time and the least supply cost. The model considers one materials demand site and multiple selectable materials supply sites. It assumes that the type and quantity of emergency materials in demand and available are known after emergency happens and there is no vehicle return when the transportation constraint exists. This paper proposes to transform the capacity constraint and optimize the decision-making process via the ideal-point method. This paper uses the ideal-point method of fussy optimization to transform the multi-objective model into a single-objective model, which objective is to find out the relative approximation between the non-inferior solution and positive-negative ideal point of whole objectives. Positive and negative ideal points are optimal and worst solutions of the single-objective model respectively. Based on the method for emergency materials dispatching proposed by Chunlin He et al, this paper proposes the method for finding non-inferior solutions, considering the constraint of transportation capacity. It calculates the relative approximation of all the non-inferior solutions, and sorts them. The non-inferior solution of the maximum of relative approximation is optimal. The solution passes the sensitivity analysis for the weight of supply time using the analytic method. The result indicates that the effect on ordering non-inferior solutions by the weight is in accordance with the ocular observation, and the method is robust and feasible. The article finally tests the feasibility and the robustness of the algorithm through numerical examples. In summary, this article proposes a method of scheduling multi-objective optimal projects for solving the depot selection problem of multiple materials. The practical and convenient algorithm with fast search speed provides a good decision-making tool for emergency logistics management.