In the article a questions about features evaluation of the quality and management of complex objects in a hierarchical structure of building are discusses. The use of fuzzy logic for these purposes includes the construction of membership functions, which describe the quality of the object of study as a linguistic shift with three terms. Two methods of constructing membership functions and features of their use is defined. For optimum quality management four most common types of membership functions is defined and their analytical description is presented. This kind of membership function, which provides the greatest sensitivity in the measurement of the quality of the object, is defined.
fuzzy logic membership functions, evaluating the quality, the degree of incidence, sensitivity