to accompany CHAPTER 14: Material Requirements Planning (MRP) and ERP.
Additional Homework Problems. 14.28 You need to schedule 10 units of product
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Additional Homework Problems to accompany CHAPTER 14: Material Requirements Planning (MRP) and ERP
14.28 You need to schedule 10 units of product Alpha for delivery in 6 weeks. Three units of D and 2 units of F are required for each Alpha. The lead time for Alpha is 1 week. Lead time for D is 1 week, and lead time for F is 2 weeks. a) Construct a product structure. b) Prepare a time-phased product structure. c) Prepare a gross requirements plan for Alpha.
14.29 Using the information in Problem 14.28 construct a net material requirements plan. There are 2 Alphas on hand and 4 Ds.
14.30 As the production schedules for an exercise equipment manufacturer, you are to schedule an order for 50 UltimaSteppers, which are to be shipped in week 8. Assume lot-for-lot ordering. Below is information about the steppers. Item Stepper A B C D E F
Lead Time 2 1 2 3 1 2 2
On Hand 20 10 30 10 15 5 20
Components A(1), B(3), C(2) D(1), F(2) E(1), F(3) D(2), E(3)
a) Develop a product structure. b) Develop a time-phased structure. c) Develop a net material requirements plan for F.
14.31 Keebock, a maker of outstanding running shoes, keeps the soles of its size-13 running shoes in inventory for one period at a cost of $.25 per unit. The setup costs are $50. Beginning inventory is zero and lead time is 1 week. Shown below are the net requirements per period. Period Net requirements
1
2 35
Determine Keebock’s cost based on a) EOQ. b) Lot-for-lot. c) Part period balancing (PPB).
3 30
4 45
5 0
6 10
7 40
8 30
9 0
10 30
11 55
14.32 Your stockroom manager, Yamil Bermudez, arrived at your desk just after you had completed the net requirements plan for product A (use data in Figure 14.16 and Problem 14.14 in the text), exclaiming that the cycle counter should be fired. It seems that the cycle counter was wrong; there are three As available now, not zero, as the original data showed; moreover, five Es are also available. About then, your boss, Sam Melnyk, who overheard the discussion, says, “You might as well extend the net requirements plan out to 16 weeks, because we just received an order for 10 more As in week 12 and 5 more in week 15. Additionally, count on the field service department wanting 3 more Bs in week 16, as well as those 10 units of B and F in week 6.” You decide to use the lead times in Problem 14.14, but item G now has a lead time of 4 weeks. Your assignment is to prepare a new net requirements plan, based on the actual inventory (as reported) and the new schedule.
