UNSBM MODEL: A MODEL FOR DEFINING UNIQUE OVERALL AND STAGE EFFICIENCIES IN DATA ENVELOPMENT ANALYSIS

This article presents a model for defining unique stage efficiencies. From the literature review of models of Network Slacks-Based Measure in Data Envelopment Analysis, issues that require further study were identified, such as the non-exclusivity of stage efficiencies, slack not necessarily being unique and projections of intermediate products not being unique. In this way, a model, called UNSBM, which defines unique and neutral efficiencies for the stages and which also considers potential conflicts between them is proposed. This model is based on the SBM-NDEA model of multipliers, follows the composition paradigm and a bi-objective approach. As for overall efficiency, stage efficiencies can be aggregated later to define it. To formulate the model, a two-stage series network configuration was considered.