solution

Consider a single machine and two job classes. The processing times of
Class 1 (2) jobs are exponentially distributed with rate λ1 = 6 ( λ2 = 12). The
weight of a Class 1 (2) job is w1 = 4 ( w2 = 3). Preemptions are not allowed.
When themachineisprocessingajobofeitheroneofthetwoclassesitissubject
to breakdowns. The up times of a machine when it is processing a Class 1 (2)
job are exponentially distributed with rate ν1 = 6 ( ν2 = 5). The repair times
after a breakdown when processing a Class 1 (2) job are arbitrarily distributed
with mean 1/μ1 = 0 .5 (1 /μ2 = 1). Which class of jobs should have a higher
priority? (Hint: See Exercise 10.11.)