Determining assurance interval for non-Archimedean element in the improving outputs model in DEA

Recently Jahanshahloo and Khodabakhshi [Appl. Math. Comput., in press] in an article, ''suitable combination of inputs for improving outputs in DEA with determining inputs congestion'', presented a model in which some inputs can be increased on the contrary of existing models in DEA. It is important to determine the value or interval of non-Archimedean @e such that envelopment form is bounded, in other words multiplier form is feasible. In this article in addition to determining assurance interval of @e for boundedness of the envelopment model, the feasibility of the multiplier model, we also provide an alternative proof for unboundedness. An illustrative example is exhibited, too.