14. The XYZ Company uses MRP to plan and schedule plant operations.

The plant operates five days per week with no overtime, and all orders are due at 8 a.m. Monday of the week required. It is now 8 a.m.

Monday of week 1, all machines are currently idle, and the production manager has been given the information in Exhibit B.

a. Assuming that the shortest operation next rule is used to schedule orders in the shop, how should the open orders (scheduled receipts)

for items A, B, and C be sequenced at their current operations? What are the implications of this schedule?

b. Assuming that the critical ratio rule is used to schedule orders in the shop, how should the open orders for items A, B, and C be sequenced at their current operations? What are the implications of this schedule?

c. Suppose that 32 additional units of item B have just been found in the stockroom as a result of a cycle count. What actions are required on the part of the MRP planner?

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EXHIBIT B System Data MRP System Data Week Item A 1 2 3 4 5 6 7 8 Gross requirements 3 16 8 11 5 18 4 2 Scheduled receipts 30 Projected available balance 10 7 21 13 2 27 9 5 3 Planned order release 30 Q-30; LT-2; SS 0. Week Item B 1 2 3 4 5 6 7 8 Gross requirements 2 5 12 4 18 2 7 10 Scheduled receipts 30 Projected available balance. 12 10 5 23 19 1 29 22 22 12 12 Planned order release 30 Q=30; LT=4;SS=0. Week Item C 1 2 3 4 5 6 7 8 Gross requirements 14 4 12 7 8 3 17 2 Scheduled receipts 20 Projected available balance 17 3 19 7 0 12 9 12 10 Planned order release 20 20 Q= 20; LT 4;SS=0. Item Routing Shop-Floor Control System Data Current Operation Number A Operation number 1 2 3 4 3 (machine 2) Machine number 4 6 2 3 Processing time 1 1 1 1 B Operation number 1 2 3 4 2 (machine 2) Machine number 4 2 6 1 Processing time 4 2 5 3 C Operation number 1 2 3 4 4 (machine 2) Machine number 6 3 1 2 Processing time 3 4 6 1.5 *In days. For computing lead times, assume that there are 1.5 days of move and queue time associated with each operation, including time to complete paperwork after the last operation.