Site selection for franchise system of service industry using fuzzy theory

Because the site-selection process concerns human being´s subjective judgment, measurement is usually fuzzy and those subjective opinion can therefore be described as triangular fuzzy number. This study extends the evaluation of site-selection applications to fuzzy environment and presents a linguistic decision-making approach to evaluate the site-selection problem with fuzzy numbers. By following the probability of fuzzy sets defined by Zadeh, the membership function of triangular fuzzy number determined by each manager with respect to each evaluation item is first calculated, and the ratio of that either on satisfied-level or on unsatisfied-level can then be calculated. For each evaluation item, the degree of each satisfaction-level can be obtained by summarizing all the ratios of all surveys in the corresponding level and the confidence index can be obtained. An example is conducted to illustrate the effectiveness of the presented approach.