A process-oriented M/M/1 queue. A customer arrives at or departs from a queue. If arriving, a new customer is scheduled, report is set, and the customer is appended to the queue. If departing, the customer is terminated and the loket is released. The server takes the first customer, acquires a loket and schedules departure. Notice that the server is made conditional and that it is never passivated, so it exists for the entire simulation, and is invoked whenever a customer is activated. See event for an event-based M/M/1 queue.