Suppose that the output (input) of evaluation DMU is invariable, its relative efficiency varies inversely to its input (directly to its output) while the input and output of reference DMUs are fixed.

• 可考查评价决策单元输入或输出变化时其效率的变化; 当参考决策单元的输入和输出不变时；若评价决策单元的输出(入)不变；其相对效率和它的输入(出)成反(正)比.