A small pizza shop has a single telephone number that can ring two different phones. Each of these phones has the capability to put a single call on hold and then whenever a call is completed the next waiting call (from either phone) will automatically ring through. The average call lasts 5 minutes and, during peak times, calls come in at a rate of one call every two minutes.
(a) What is the state space for this queuing system?
(b) What is the steady-state distribution for this queuing system? (Hint: you should determine what type of queuing system this is and then find its steady-state distribution.)
(c) The owner of the pizza shop is contemplating adding an additional phone line. Do you think the owner should? Why or why not?