  Data Envelopment Analysis (DEA) is a multi-criteria technique based on linear
programming to deal with many real-life problems, mostly in nonprofit
organizations. The slacks-based measure (SBM) model is one of the DEA model
used to assess the relative efficiencies of decision-making units (DMUs). The
SBM DEA model directly used input slacks and output slacks to determine the
relative efficiency of DMUs. In order to deal with qualitative or uncertain
data, a fuzzy SBM DEA model is used to assess the performance of DMUs in this
study. The credibility measure approach, transform the fuzzy SBM DEA model into
a crisp linear programming model at different credibility levels is used. The
results came from the fuzzy DEA model are more rational to the real-world
situation than the conventional DEA model. In the end, the data of Indian oil
refineries is collected, and the efficiency behavior of the companies obtained
by applying the proposed model for its numerical illustration.
