Department Of Mathematics, IIT Roorkee,Roorkee,India
The present investigation presents a stochastic model for a flexible manufacturing system consisting of flexible machine, loading/unloading robot and an automated pallethandling device. We consider unreliable flexible manufacturing cell (FMC) wherein machine and robot operate under individual as well as common cause random failures. The pallethandling system is completely reliable. The pallet operation times, loading/unloading times and material handling times are considered to be random and exponentially distributed. By constructing governing equations for various system states at equilibrium, the steady-state probabilities are obtained. Some system characteristics namely utilization rate of the handling system, utilization rate of the production machine and utilization rate of the robot etc. are obtained. Some special cases are also discussed for reliable and unreliable cells. Sensitivity analysis is facilitated to examine the effect of parameters on system performance by taking numerical illustration.