A manufacturing cell has four identical machines where jobs can be run on any of the

machines. Jobs arrive according to a Poisson process with a rate of $\backslash$lambda $=4$ per hour. All jobs

have the same service rate $\backslash$mu $=3$ per hour, and the distribution of service times is assumed to

be exponential. No jobs may be awaiting work in the cell, so at most $4$ jobs may be present

in the cell at a given time.