We investigate the resolution of fuzzy (relational) equation systems with tolerances which are a certain extension of fuzzy equations considered f.i. in [3-5]. The extension of the concept of Higashi and Klir [3] enables us to describe the set of solutions to our problem (for given tolerances) by means of posets. In a second part we investigate an inverse problem: Given upper (lower) tolerances how to determine lower (upper) tolerances such that the arising problem becomes consistent? Numerical examples are given.
