=+13. Figure 5.33 is the overlay of a machining cell consisting of four identical machining centres which are loaded and unloaded by a robot (supplied as CELL.OLY on Demonstration Diskette No.1). Each loading operation will take 10 seconds to complete, and each unloading 8 seconds. Parts arrive at random according to the distribution given below.

Inter-arrival times No. of observations 220 110 110 80 70 40 60 60 50 40 20 The machine times are distributed as follows:

Machining times No. of parts 90 150 110 110 80 70 70 60 60 50 40 20 Time (min)
1 4 8 12 14 17 19 25 27 35 45 60