Consider a bus station where customers arrive in pp(λ) fashion. busses arrive empty one after another in pp(µ) fashion. each bus has capacity to carry a maximum of k customers. when a bus arrives at the station, if there are x customers waiting then the bus departs instantaneously with min(x, k) passengers. let x(t) be the number of customers waiting at the station at time t. model {x(t), t ≥ 0} as a ctmc.