HAL computer has a printed circuit board line with $2$ stations. The first station $($resist

apply$)$ applies a photoresist material to the circuit boards. The second station $($expose$)$

exposes the boards to UV radiation to produce a circuit pattern that is later etched

onto the boards. Analysis of the line shows that resist apply has an average process

time of $8$ minutes with a coefficient of variation of $1\mathrm{.}0,$ and expose has an average

processtime of $14$ minutes with a coefficient of variation of $2\mathrm{.}0.$ Also, and not included

in the process times, resist apply has an MTTF of $15$ hours and an MTTR of $20$ hours

both based on an exponential distribution, while expose has an MTTF of $1$ hour and

MTTR of $14$ minutes. Jobs arrive at the resist with an arrival rate of $1$ job per hour with

an arrival coefficient of variation of $2$