Abstract
Flow-line systems with blocking are often encountered in the real world that fills the fuzziness. This paper proposes a mixed integer nonlinear programming approach for evaluating the performances of the flow line system with blocking in fuzzy environments. The main idea is to model this system as a single-channel, multiple phase queueing model with finite capacity, in that the arrival rate and service rates are fuzzy numbers; then transform this to a family of conventional crisp queues by applying the alpha-cut approach in fuzzy theory. On the basis of alpha-cut representation and the extension principle, two pairs of mixed integer nonlinear programs are formulated to calculate the lower and upper bounds of the fuzzy performance measures at possibility level alpha, via which the membership functions of the performance measures are derived. An example is investigated successfully to illustrate the validity and the informative benefits of using the proposed approach. Since the performance measures are expressed by membership functions rather than by crisp values, the fuzziness of input information is conserved completely, and more information is provided for capacity planning in flow line systems. Furthermore, managerial implications of the analyses are also examined.
