A Conceptual Model Based on the Fuzzy Set Theory to Measure and Evaluate the Performance of Service Processes

Correct measurement and evaluation of service processes is still an enormous challenge for companies. Especially the need for interaction between customer and supplier during the production of a service makes it difficult to measure and evaluate services. In this context soft factors (like friendliness and competence of the employees) play an important role. The measurement and evaluation of soft factors is very challenging. Soft factors cannot be measured by using objective measuring equipment (like the measurement of throughput time with the aid of a stop watch). Soft factors rather have to be measured and evaluated by people. Here people function as subjective measuring equipments. The use of Liker scales is the common way to measure and evaluate soft factors. But Likert scales do not sufficiently consider human perception. The current paper presents a conceptual five stage model based on the fuzzy set theory to measure and evaluate the performance of service processes. Fuzzy sets are an extension of classical sets and allow elements to belong gradually to a set. This characteristic of fuzzy sets is used to objectify the measurement and evaluation procedure of service processes.