Fuzzy models and relational equations

We consider a problem of system modelling expressed mathematically in terms of fuzzy sets, especially fuzzy relational equations. A general methodological scheme is proposed and, as a sequel, particularized in the form of a sequence of several steps, such as: (i) structure determination, (ii) parameter determination and (iii) model validation. Procedures for studying and detecting a data structure are given special attention. New schemes are proposed. Moreover, several examples indicating fields of application of fuzzy models are considered.