决策单元的投影问题研究

The Research on the Problem of Projections for DMUs

在传统的DEA模型中,不论是最优相对效率模型或者最差相对效率模型,它们研究投影问题都是在不同的约束域内进行的,得出的结论都有一定的片面性.在bounded DEA模型中,决策单元的效率计算是在一个区间内进行的,可以同时研究非DEA有效的决策单元在有效前沿面上的投影和非DEA无效的决策单元在DEA无效面上的投影,得出的结论更加科学合理,并以定理的形式给出了投影结果的表达式.通过一个实例将投影结果与传统模型中得出的投影结果进行了比较,发现bounded DEA模型得到的投影结果对实际的生产具有更强的指导意义.

In conventional DEA models, the best relative efficiency model or the worst relative efficiency model, the projection for Decision Making Units （DMUs） is studied in different constraint domains. Thus, the conclusion is one-sieded. The efficiencies of DMUs are measured in an interval and the projections of non-DEA efficient DMUs on DEA efficient frontier and non-DEA inefficient DMUs on DEA inefficient frontier could be studied at the same time in bounded DEA model. Two theorems is given as the expressions of projections. The results of projections, obtained from bounded DEA model, give more good suggestions in practice than that from conventional DEA models by a numerical example.