Comment on the customer service and inventory performance of the two rules. SPT rule was best according to two of the measures of effectiveness. SPT is always superior in terms of minimizing flow time and, hence, in terms of minimizing the average number of jobs at the work center and completion time. This results in faster job completion, which has the potential to generate more revenue. From the above two schedules and its respective calculations, we can observe that SPT schedule results in lower average flow time, lower past due hours and lower average number of jobs than EDD. Because the SPT rule always results in the lowest average flow time, it can result in lower in-process inventories. And because if often provides the lowest average tardiness, it can result in better customer service levels. Finally, since it always involves a lower average number of jobs at the work center, there tends to be less congestion in the work area. What trade-offs should management consider in selecting rules for scheduling the welding machine in the future. However, due dates are often uppermost in mangers minds, so they may not use SPT because it doesn’t incorporate due dates. SPT rule also tends to make long jobs wait, perhaps for longer times. The EDD scheduling takes care of the due dates minimizing the lateness. Hence, the level of customer satisfaction increases with EDD because it takes care of the due dates and processes as per the due dates of the jobs.