A critical resource in a manufacturing operation experiences a very high traffic intensity during the shop’s busiest periods. During these periods the arrival rate is approximately 57 jobs per hour. Job processing times are approximately exponentially distributed with mean 1 minute.

a. Compute the expected flow time in the system assuming an FCFS processing discipline, and the expected flow time under SPT using Figure 9–13.

b. Compute the probability that a job waits more than 30 minutes for processing under FCFS.

c. Using a normal approximation, estimate the probability that a job waits more than 30 minutes for processing under LCFS.