Assignment:
Product A requires one B component and two C components to make. The lead time for Product A is one week, while the lead time for component B is two weeks. The lead time for component C is one week.
The demand forecast for product A is as follows:
Table: Weekly demand forecast for A
|
Week
|
1
|
2
|
3
|
4
|
5
|
6
|
|
Demand Forecast
|
165
|
190
|
130
|
230
|
150
|
200
|
The available inventory at the beginning of week 1 for A,B, and C is 80, 50, and 200 units respectevely. The scheduled order receipts for each item is
A: 140 units in week 1
B: 200 units in week 1 and 140 units in week 2
C: 400 units in week 1 units respectively.
Suppose the lot sizing rule for each item is as follows:
A: Lot for Lot A
B: Silver meal heuristic (A=200, h=1)
C: Part-period balancing (A=300, h 0.5)
Assume that shortages cannot be backordered and that the company wishes to maintain a safety stock of 50 parts of A and B and 100 parts of C at all times.
1. If the current time is the end of week 0, perform MRP calculations for all items until the end of week 6
2. Suppose it is now the end of week 1. The realization of demand for item A in week 1 was 200 units and the demand forecast for week 7 is 240 while all other forecasts are unchanged. Perform the MRP calculations for the three items. (Note that, for the item with L weeks lead time, the order released in week 1 will become the scheduled receipts in the week L+1.) Are there any problems with your MRP calculations? If yes, how would you handle the situations so that the production plan will be feasible?