University of Guilan Journal of Mathematical Modeling 2345-394X 14 1 2026 03 01 New non-radial models for merger and acquisition to achieve strong efficiency and MPSS without changing in the efficient frontier 35 55 9034 10.22124/jmm.2025.30974.2781 EN Ali Reza Fakharzadeh Jahromi shiraz university of technology Hassan Rostamzadeh Department of OR, Faculty of Mathematics, Shiraz University of Technology, Shiraz, Iran Journal Article 2025 06 18 In this study‎, ‎new models for the merger of two or more inefficient units are presented‎. ‎The discussed mergers in this study are horizontal and acquisition mergers‎. ‎In the presented models‎, ‎unlike the previously presented models‎, ‎the mergers are done non-radially; indeed‎, ‎managers can manage each of the indicators separately in the presented new merger process‎. ‎In this regard‎, efficient frontier of the production possibilities set does not change‎, ‎and merger of several units does not affect the efficiency score of other decision-making units‎. ‎Also‎, ‎by merging via the new models one can obtain a strong efficient unit with the most productive scale size‎. ‎The presented models are applied to the horizontal and acquisition merger of Iranian banks. https://jmm.guilan.ac.ir/article_9034_d3f7caae6f4681a0520844959494ce41.pdf