Measuring flexibility of computer integrated manufacturing systems using fuzzy cash flow analysis

There exist a number of methods proposed in the literature to quantify manufacturing flexibility in monetary terms and to use a financial evaluation model with a decision criterion based on present worth. However, most of these methods are unable to handle problems with incomplete and uncertain data. To obtain a sensible result in quantifying the manufacturing flexibility in computer integrated manufacturing systems, this paper proposes some fuzzy models based on fuzzy present worth. 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. To build such a model, fuzzy present worth formulas of the manufacturing flexibility elements are formed. Flexibility for continuous improvement, flexibility for trouble control, flexibility for work force control, and flexibility for work-in-process control are quantified by using fuzzy present worth analysis. Formulas for both inflationary and non-inflationary conditions are derived. Using these formulas, more reliable results can be obtained especially for such a concept like flexibility that is described in many intangible dimensions. These models allow experts' linguistic predicates about computer integrated manufacturing systems.