Sub-units Chain in the DEA

In this paper, we consider the problem of evaluating the efficiency of a company, DMU, initially having sub-units, DMSU, for fulfilling their requirements in these internal subunits. This is similar to the methods of producing different items in a chain system, in which all the parts are provided in other related sections of the chain system. In fact, the output of every sub-unit in this system produces the internal input for the following subunits in the chain. We demonstrate the efficiency of all sub-units and finally the aggregate efficiency of them at large.