The customer orientation philosophy of modern business organizations and the implementation of the main principles of continuous improvement, justifies the importance of evaluating and analyzing cust omer satisfaction. In fact, customer satisfaction isconsidere d today as a baseline standard of performance and a possi ble standardo f excellence forany business organization. Extensive research has defined several alternative approaches, which examine the customer satisfaction evaluation prob lem from very different perspectives. These approaches include simple quantitative tools, statistical and data analysis techniques, consumer behavioral models, etc. and adopt the following main prin ciples: * The data of the problem are based on th e customers' judgments and are directly collected from them. * This is a multivariate evaluation problem given that customer's overall satisfac tion depends on a setof variables representing product/service characteristic dimensions. * Usually, an additive formula is used in order to aggregate partial evaluations in ano verall satisfaction measure. Many of the aforementioned approaches don ot consider the qualitative form of customers' judgments, although this information constitutes the main satisfaction input data. Furthermore, insev eral cases , the measurements are not sufficient enough to analyze in detail customer sa tisfaction because models' results are mainly focused on a simple descriptive analysis.

The customer orientation philosophy of modern business organizations and the implementation of the main principles of continuous improvement, justifies the importance of evaluating and analyzing cust omer satisfaction. In fact, customer satisfaction isconsidere d today as a baseline standard of performance and a possi ble standardo f excellence forany business organization. Extensive research has defined several alternative approaches, which examine the customer satisfaction evaluation prob lem from very different perspectives. These approaches include simple quantitative tools, statistical and data analysis techniques, consumer behavioral models, etc. and adopt the following main prin ciples: * The data of the problem are based on th e customers' judgments and are directly collected from them. * This is a multivariate evaluation problem given that customer's overall satisfac tion depends on a setof variables representing product/service characteristic dimensions. * Usually, an additive formula is used in order to aggregate partial evaluations in ano verall satisfaction measure. Many of the aforementioned approaches don ot consider the qualitative form of customers' judgments, although this information constitutes the main satisfaction input data. Furthermore, insev eral cases , the measurements are not sufficient enough to analyze in detail customer sa tisfaction because models' results are mainly focused on a simple descriptive analysis.