A service systems having numerous functioning states

The article concerns a queueing system in which the serving system has numerous functioning states in both stationary and nonstationary modes. The customer flow is assumed Possion; the time of serving every customer is a random quantity which is arbitrarily distributed; the serving system fails at a constant rate which depends on its state and functioning mode; the serving system restoration time is also a random arbitrarily distributed quantity; the queueing time and the queue length aire notlimited.