Iranian Journal of Optimization, 11(2), 77-84, December 2019 Merging DMUs Based on of the Idea Inverse DEA Department of Mathematics, Khomeinishahr Branch, Islamic Azad University, Khomeinishahr, Isfahan, Iran Abstract In this paper, we propose a novel method using multiple-objective programming problems to answer the following question: if among a group of decision making units (DMUs), a subset of DMUs are re- quired to merge and form a new DMU with specific input/output lev- els and a predefined efficiency target, how much should be the outputs/inputs of the merged DMU? This question answered accord- ing to the concept of inverse DEA. Sufficient conditions are estab- lished for input/output-estimation of the merged DMU using multiple-objective programming problems. A numerical example with real data is presented to illustrate the goals of this paper. Elaheh Zeinodin and Saeid Ghobadi * Received: 23 January 2018 Accepted: 26 August 2018 Keywords: Data Envelopment Analysis (DEA) Efficiency Inverse DEA Multiple-Objective Program- ming (MOP) Merging decision making units (DMUs) Iranian Journal of Optimization Volume 11, Issue 2, 2019, 77-84 Research Paper Islamic Azad University Rasht Branch ISSN: 2588-5723 E-ISSN:2008-5427 *Correspondence E-mail: ghobadi@iaukhsh.ac.ir Online version is available on: www.ijo.iaurasht.ac.ir 77