3-PHASE QUEUING SERVICING SYSTEM WITH RENEWABLE SERVERS

A three-phase queueing servicing system is considered in this paper. T he servers can fail during their occupation time. A failed server is s ent to be repaired immediately. The stationary probabilities of the di fferent states of the system are studied under the assumption that the arrival rime, service time, failure time and repair time of the serve rs all have a Poisson distribution with different parameters. Also the mathematical expectation of the number of customers in each phase is obtained. Finally, the results in Mokaddis et al., Ninth International Congress for Statistics, Computer Science, Social and Demographic Res earch, Ain Shams University, 31 March-10 April, 1984, are obtained as special cases from the results in this paper. (C) 1997 Elsevier Scienc e Ltd.