Operations Management: Processes and Supply Chains, 12th Edition

Solved Problem 3

1. Revisit Example 10.3, where the consulting company has five jobs in its backlog. Create a schedule using the EDD rule, calculating the average days past due and flow time. In this case, does EDD outperform the FCFS rule?

Solution

1. Customer Sequence	Start Time (days)	Processing Time (days)	Finish Time (days)	Due Date	Days Past Due	Days Ago Since Order Arrived	Flow Time (days)
   B	0	$+$	16	$=$	16	27	0	12	28
   A	16	$+$	25	$=$	41	29	12	15	56
   D	41	$+$	10	$=$	51	48	3	10	61
   C	51	$+$	14	$=$	65	68	0	5	70
   E	65	$+$	12	$=$	77	80	0	0	77

   The days past due and average flow time performance measures for the EDD schedule are

   $$\text{Average days past due}=\frac{0+12+3+0+0}{5}=3.0\text{ days}$$

   $$\text{Average flow time}=\frac{28+56+61+70+77}{5}$$