具单周期特性的短生命周期产品随机IRP及算法

为优化企业物流系统，针对单周期，短生命周期产品的特点，将库存控制与配送路径安排决策集成，考虑随机需求、缺货成本、积压贬值成本、配送成本等，建立一个具有单周期特性的短生命周期产品随机IRP离散模型，目标是合理确定各零售门店的订购数量及配送路线使得系统成本最小。该问题属于NP-hard问题。对此，采用“报童模型”和差分法求解最佳订购量，将模型予以转化，并设计了一种遗传算法进行求解。算例结果表明所提算法能在较短时间内求解出不同客户数目组合的满意解。结论是：门店订购量宜采用组合选择方式；系统成本与单位行程运价正相关；车容量增大有助于降低系统成本。

Stochastic IRP and algorithm for short life-cycle products with characteristic of single cycle

In order to improve the enterprise logistical system, a joint IRP model with stochastic demands is built based on the characteristics of single cycle and short life-cycle products, considering shortage costs, inventory backlog depreciation costs and distribution costs. The goal is to determine a reasonable order quantity and distribution route of each retail store to minimize system cost. The problem belongs to NP-hard problem. So, the “newsboy model” and “difference method” are applied to solve the optimal order quantity, and transform the model. Then, a genetic algorithm is designed to solve the model. The numerical results show that the satisfactory solution can be obtained by the proposed algorithm in a relatively short period with different number of customers. The conclusions can be generalized as fellows: the store order quantity should be set with portfolio choice method, the system costs are correlated positively with unit transportation price, the increasement of vehicle capacity is helpful to reduce system costs.