Abstract
In the present investigation, we study the performance analysis of a machine repair system operating under admission control F-policy in fuzzy environment. As per F-policy, when the system reaches its full capacity K, no further failed machines are allowed to join the system until the system size ceases down to a prespecified threshold value F. To deal with general reattempts made by a failed machine from the orbit for the repair, the supplementary variable corresponding to retrial times is used to construct the steady-state governing equations, and then explicit formulae for the queue size probability distributions are derived by using Laplace transform and recursive method. A fuzzy cost function is formulated by considering the cost elements as trapezoidal fuzzy numbers and then α − cut approach is implemented to develop lower and upper bounds of the cost elements. In order to defuzzify the cost function, the signed distance method is used. The genetic algorithm is applied to determine the optimal control parameter and corresponding minimum cost of the system.