Fuzzy control chart analysis of mean waiting time in M / M / S queuing model

Queuing problems are most common features not only in our daily-life situations such as bank counters, post offices, ticket booking centers, public transportation systems, but also in more technical environments such as in manufacturing, computer networking and telecommunications. The main observable performance characteristics for any queueing system are length and waiting time. Control chart is a graphical technique used to monitor changes in process over time and signifies to evolve methods to control. To deal with practical situations the control chart with fuzzy parameters are much more realistic than that of assumed classical crisp parameters. In this paper for M/M/s queueing model control limits are established for the mean waiting time of customers both in queue and in the system under fuzzy environment. Numerical illustrations are given to highlight its applications.