Jobs Needing Repair
A system consists of a service facility and a repair facility. The service time at both facilities is Exp($\frac{1}{10}$). Jobs arrive at the service facility according to a Poisson process with rate λ. After each visit to the service facility, the job either:
• leaves the system (probability 0.1)
• requires repair (probability 0.01)
• revisits the service facility (probability 0.89).
After completing repair, a job returns to the service facility, except that now, after each visit to the service facility, the job either:
• leaves the system (probability 0.1)
• requires repair (probability 0.5)
• revisits the service facility (probability 0.4).
Please answer the following questions about the system:
(a) What is the expected number of times that a job visits the service facility?
(b) What is the highest possible throughput, λ?
(c) Set λ = $\frac{1}{200}$. What is the expected time in system, E[T]?