Question

Question 2

“The percent idle time of your system is 15” Explain the sentence by giving eamles of ? and µ.

The Rockwell Electronics Corporation retains a service crew to repair machine breakdowns that occur on an average of ? = 3 per day (approximately Poisson in nature). The crew can service an average of µ = 8 machines per day, with a repair time distribution that resembles the exponential distribution.

What is the utilization rate of this service system?

What is the average downtime for a machine that is broken?

How many machines are waiting to be serviced at any given time?

What is the probability that more than one machine is in the system? Probability that more than two are broken and waiting to be repaired or being serviced? More than three? More than four?

Answer 1

a)

= 3

= 8

utilization rate of this service system = / = 3/8 = 0.375

b)

average downtime for a machine that is broken = 1/( - ) = 1/(8-3) = 1/5 = 0.2

c)

number of machines are waiting to be serviced at any given time

= Lq = ^2/( ( - ))

= 0.225