Quantification of flexibility in advanced manufacturing systems using fuzzy concept

Unlike classical logic which requires a deep understanding of a system, exact equations, and precise numeric values, fuzzy logic incorporates an alternative way of thinking, which allows modeling complex systems using a higher level of abstraction originating from our knowledge and experience. To obtain a sensible result in quantifying the manufacturing flexibility, this paper proposes some fuzzy models based on fuzzy present worth and fuzzy mathematical programming. The fuzzy models based on present worth are basically engineering economics decision models in which the uncertain cash flows and discount rates are specified as triangular fuzzy numbers. Fuzzy present worth formulae of the manufacturing flexibility elements are formed. Using these formulae, more reliable results can be obtained especially for such a concept like flexibility that is described in many intangible dimensions. The fuzzy models based on fuzzy mathematical programming allow decision-makers use upper and lower bounds for the attainment of the objectives and soft constraints. These models allow experts' linguistic predicates about advanced manufacturing systems. (C) 2003 Published by Elsevier B.V.