OPMT 620 17

1. Freight car loadings during an 18-week period at a port are:

Week	Number
1	220
2	245
3	280
4	275
5	300
6	310
7	350
8	360
9	400
10	380
11	420
12	450
13	460
14	475
15	500
16	510
17	525
18	541

a. Plot the data to determine their pattern.

b. Forecast loadings for week 19 using each of the following:

- a three-week moving average

- a weighted moving average using the following weights: 0.5 for week 16, 0.2 for week 17, and 0.3 for week 18.

- Exponential smoothing with trend with alpha = 0.2 and beta = 0.4

2. A company produces two types of products named (A) and (B). The production process for each product is similar in that both require a certain number of hours of electronic work and a certain number of labour-hours in the assembly department. Each product (A) takes 4 hours of electronic work and 2 hours in the assembly shop. Each product (B) requires 3 hours in electronics and 1 hour in assembly. During the current production period, 240 hours of electronic time are available, and 100 hours of assembly department time are available. Each product (A) sold yields a profit of $7; each product (B) produced will be sold for a $5 profit. Please determine the best possible combination (production quantity) of products (A) and (B) to manufacture to reach the maximum profit.

3. Given the following forecasts and steady regular output of 550 every month for aggregate production plan, what total cost would result if overtime is limited to a maximum of 40 units per month, and subcontracting is limited to a maximum of 10 units a month? Please provide the aggregate production plan.

Month	1	2	3	4	5	6
Forecast	540	540	570	590	600	580

Regular output cost per unit = $20

Overtime cost per unit = $30

Subcontract cost per unit = $25

Unit holding inventory cost per month = $10

Unit back-order cost per month = $18

4. A flower shop uses 250 clay pots a month. The pots are purchased for $2 each. Annual holding cost is estimated to be 30 percent of purchase cost, and ordering cost is $20 per order.

a. Calculate the EOQ

b. Calculate the EOQs total inventory cost.

c. If the manager has been currently using an order quantity of 250 flower pots, what additional annual inventory cost is the shop incurring by using the current order quantity?