Question 2. Material Requirements Planning (35 marks)

	Week
	1	2	3	4	5	6	7	8	9	10
Gross requirements	40	50	20	10	30	80	70	60	100	20

The MRP gross requirements for product A in the next 10 weeks are shown in the following table. The lead time for A is three weeks, and the setup cost is $300. The carrying cost is $2 per unit per week. Suppose the initial inventory at the beginning of week 1 is 150 units.

Questions:

(1) Determine for what quantity the order should be planned to be received for each week using the following three lot-sizing methods: lot-for-lot, least total costs, and least unit cost. (Hint: start from the week when the initial inventory is insufficient to satisfy the gross requirements).

Lot for lot	Week
	1	2	3	4	5	6	7	8	9	10
Planned order receipts

Least Total Costs	Week
	1	2	3	4	5	6	7	8	9	10
Planned order receipts

Least Unit Cost	Week
	1	2	3	4	5	6	7	8	9	10
Planned order receipts