An improvement to the relative efficiency with price uncertainty

This article describes the method of measurement of relative efficiency, when the input and output prices are unknown .In a situation , where only the bound of input prices for the cost efficiency and the bound of output prices for the revenue efficiency are known, measurement of relative efficiency consists of two cases: optimistic and pessimistic perspective. The main object of this article is to study the pessimistic relative efficiency that eventually, with the computation of assessment of optimistic, it gives interval efficiency for each DMU.