We consider a single server retrial queueing system with variant working vacations and vacation interruption where the regular busy server is subjected to breakdown due to the arrival of negative customers. As soon as the orbit becomes empty at the time of regular service completion for a positive customer, the server takes at most J number working vacations until at least one customer is received in the orbit when the server returns from a working vacation. During the working vacation period, the server serves at a lower speed service rate (µv<µb). Using the method of supplementary variable technique, we determined the steady state probability generating function for the system and its orbit. We also obtained some analytical expressions for various performance measures such as system state probabilities, the mean orbit size, the mean system size, and reliability measures of this model. Finally, some numerical examples are presented.
