an alternative 2-phase method for evaluating of dmus using dea

computationally, selection of a proper numerical value for infinitesimal non archimedean epsilon in dea models has some difficulties. although there are several algorithms for selecting the proper non-archimedean epsilon, it is important to introduce methods in order to calculate the efficiency of dmus without using epsilon. one of these methods is a two-phase method, which obtains the efficiency of each dmu through solving two lps, which the second lp is depended to the first. this paper proposes a method, which is able to compute the efficiency of dmus by two lps, which are not depended to each other and computationally can solve in a parallel computation. the major of this method is to find two references for each unit and combine them to obtain actual reference.