具有双重角色和非期望要素的供应商评价两阶段DEA模型

在基于DEA方法的供应商评价过程中，会出现供应商同时具有双重角色要素和非期望输出要素的情形。文章提出了一个处理双重角色要素的新思路，认为DEA模型中双重角色要素同时扮演了输入和输出两个角色，所有双重角色要素本质上就是网络DEA模型中的中间变量，并同时认为包含双重角色要素的生产系统一定能分解成为多个子系统，其中的双重角色要素既是一个子系统的输入，同时又是另一个子系统的输出。为测度供应商的效率，基于已有关系型两阶段DEA模型，将供应商的生产运营视为两阶段过程，其双重角色要素视为两阶段过程的中间变量，并通过将所有输出以加权和的形式表达，但对非期望输出用负的权重的方式，提出了一个具有双重角色和非期望输出要素的供应商评价两阶段DEA模型，最后用一个实例验证了方法的可行。

A Two-stage DEA Model for Evaluation of Supplier with Dual-role and Undesirable Output Factors

The situation that supplier simultaneously has dual-role and undesirable output factors would arise, during supplier evaluation based on DEA. A new idea is proposed for processing dual-role factor in present paper. Dual-role factor act as input and output role simultaneously in DEA model, and all dual-role factors essentially are intermediate variables of network DEA model; to move forward a single step, production system with dual-role factors certainly can be decomposed into multiple subsystems, and anyone dual-role factor is both an input of a subsystem and a output of another subsystem.To measure the efficiencies of suppliers, based on existed relational two-stage DEA model, production and operation of suppliers are treated as two-stage process, and dual-role factors of suppliers are treated as intermediate variables of two-stage process, by virtue of expressing all output factors as weighted sum, whereas the weight of undesirable factors being negative, a two-stage DEA model for evaluation of supplier with dual-role and undesirable output factors is proposed.A real example with 18 third-party logistics providers verifies reasonability and feasibility of the method. The related attributes for 18 third-party logistics providers are partially taken from related attributes of literature10] 25]. In this example, the input is total cost of shipments, and undesirable output is parts per million of defective parts, and desirable output is revenue, and dual-role factor is supplier capability. The contribution of the present paper consists in two aspects, one is the processing of dual-role factor, a new idea and method is proposed in the processing, the other is that a two-stage DEA model for evaluation of supplier with dual-role and undesirable output factors is proposed.