Process efficiency of two-stage systems with fuzzy data

In this paper, a new approach to compute estimations of the process efficiencies in two-stage systems with fuzzy data is presented. The first step is to compute the upper and lower limits of the α-cuts of the system efficiency using the corresponding models in Kao and Liu (2011) [14]. The second step consists in computing the upper and lower limits of the α-cuts of the efficiency of each of the processes. The upper limit of the α-cuts of the efficiency of each process is computed subject to the upper limit of the system efficiency while the lower limit of the process efficiency is computed subject to the lower limit of the system efficiency. The proposed approach takes into account the inherent uncertainty regarding the process efficiencies even in the crisp data case. The approach is illustrated with a dataset from the literature.