中文摘要：

在传统的DEA模型中,最优相对效率模型是在不大于1的范围内研究决策单元的效率的,最差相对效率模型是在不小于1的范围内研究决策单元的效率,这两种模型在研究投影问题时,是在不同的范围内进行的,有一定的片面性.将在interval DEA模型中,研究决策单元的投影问题,该模型是在相同的约束域内研究最优和最差相对效率模型,得出的结论将更加全面,通过两个定理给出了非DEA有效的决策单元在DEA有效面上的投影表达式和非DEA无效的决策单元在DEA无效面上的投影表达式.同时,通过一个实例对决策单元在interval DEA模型中的投影结果与在传统的DEA模型的投影结果进行了比较,发现投影结果比传统模型得到的投影结果对实际的生产有更强的指导意义.

英文摘要：

In conventional DEA model,the relative efficiencies of DMUs（decision making units） are measured within the range of no more than one and that of no less than one in the best relative efficiency model and the worst relative efficiency model,respectively.The results of projection for DMUs,whose efficiencies are evaluated in different ranges,are one-sided. This paper will give all-sided results of projection in interval DEA model in which the best and worst relative efficiencies are measured in the same constraint field.The expressions of projections for non-DEA efficient DMUs on DEA efficient frontier and non-DEA inefficient DMUs on DEA inefficient frontier are given by two theorems.The results of projections for DMUs obtained from interval DEA model can give much better suggestion in application than that from conventional DEA model by an example.