Group Malmquist Productivity Index, focusing on local and global role of groups: A case study of banking industry

Evaluating the performance of the groups of decision-making units (DMUs) in an organization and ranking them is very important because the groups are the basic components of organizations. Also, assessing the performance of groups and finding their strengths and weaknesses affect the future decisions of the organization. Most previous research has been done on the Malmquist productivity index of decision- making units to evaluate productivity changes of them. In practical evaluation problems, although decision units are homogeneous in many organizations, in the sense that they produce similar outputs by receiving the same input sources; However, these units are classified into different groups based on management strategies and environmental conditions. In this paper, we want to develop the Malmquist productivity index for a group of DMU’s and examine the productivity changes of groups. We also identify local and global factors that affect changes in group productivity. Finally, to explain the applicability of the proposed index, a case study is presented on the evaluation of bank branches in different regions.