Consider the M/M/s model with a mean arrival rate of 10 customers per hour and an expected service time of 5 minutes.

Use the Excel template for this model to obtain and print out the various measures of performance (with t 10 and t 0, respectively, for the two waiting time probabilities) when the number of servers is 1, 2, 3, 4, and 5. Then, for each of the following possible criteria for a satisfactory level of service (where the unit of time is 1 minute), use the printed results to determine how many servers are needed to satisfy this criterion.

(a) Lq 0.25

(b) L 0.9

(c) Wq 0.1

(d) W 6

(e) P{q 0} 0.01

(f) P{ 10} 0.2

(g)

s n0 Pn 0.95