The operations manager at Macks's Printing Shop has 5 large orders to process. Macks does Graphics, Printing, and Binding work. The shop is organized so that the Graphics work is always done before the Printing which is done prior to any Binding. The orders, to be processed, are as follows:

If multiple orders are waiting to be processed at the same Operation, at any point in time, the manager wants to use SPT to determine which order has processing priority at that particular operation.
(a). What is the average length of time that an order remains at Macks?
(b). What is the total Time each order must spend waiting for processing?
(c). What is the Average Number of orders in the processing center, assume that, upon completion, each order is immediately delivered to the customer?
(d). On average, what proportion of the time is Macks's facility being utilized?

Order # Operation Time (hours) Graphics Printing Binding 2 13