measuring interval efficiency in convex hull of data using dea

In this paper a model is introduced to evaluate decision making units (dmus) in the production possibility set (pps), with three properties namely(a) the observation ,belongs to pps. (b) any convex combination of observation in pps belongs to pps. (c) pps is the smallest set satisfying the principles (a) and (b). then we studied the effect of imprecise data in the convex hull of dmus model (chd). we analyzed the efficiency frontier in chd model with imprecise data. we have applied the first and second method in chd model for interval data. we have presented first the effect of interval data in the chd model. finally, an example has been presented for analyzing the chd model with interval data. in this example efficiency is calculated on the convex hull with first method and second method.