The simulation RUN is started by having the first car ENTER
the carwash (edge from RUN to ENTER). If the ENTERing car
finds the washing bay idle(Sɬ), service will START immediately
(edge from ENTER to START). Each time a car ENTERs the
carwash, the next car will be scheduled to ENTER ta minutes
later (edge from ENTER to ENTER).
The START service event will always schedule a car to LEAVE
after ts minutes (edge from START to LEAVE). Finally, if there
are cars waiting in line when a car LEAVEs (Qɬ), the washing
bay will START servicing the next car right away (edge from
LEAVE to START).