Reference no: EM132232983
An ophthalmologist’s office operates 52 weeks per year. It purchases disposable contact lenses for $11.70 per pair. The following information is available about these lenses.
Demand = 90 pairs/week
Order cost = $54/order
Annual holding cost = 27% of purchasing cost
Desired cycle-service level = 80%
Lead time = 3 weeks
Standard deviation of weekly demand = 15 pairs
Current on-hand inventory is 320 pairs, with no open orders or backorders.
Part I Currently, the company uses a continuous review system,
What is the EOQ? What would be the average time between orders (in weeks)?
What should be the safety stock? What should the reorder point be?
An inventory withdrawal of 10 pairs was just made. Is it time to reorder?
The store currently uses a lot size or 500 unites (i.e., Q = 500). What is the annual holding cost of this policy? Annual ordering cost?
What would be the annual cost saved by shifting from the 500-unit lot size to the EOQ?
Suppose that the weekly demand forecast of 90 pairs is incorrect and actual demand averages only 60 pairs per week. How much higher will total costs be, owing to the distorted EOQ caused by this forecast error?
Suppose that actual demand is 60 pairs but that ordering costs are cut to only $6 by using electronic data interchange to automate order placing. However, the buyer doesn’t tell anyone, and the EOQ isn’t adjusted to reflect this reduction in S. How much higher will total costs be, compared to what they could be if the EOQ were adjusted?
Part II If the company chooses to review and replenishment inventory every 5 weeks,
a. To achieve the same 80% cycle-service level, how much more safety stock is needed than with the continuous system?
b. What should be the target inventory at each review period?
It’s time for the periodic review. With the current inventory of 320 pairs, how much should be ordered?
Problem 2:
The local supermarket buys lettuce each day to ensure really fresh produce. Each morning any lettuce that is left from the previous day is sold to a dealer that resells it to farmers who use it to feed their animals. This week the supermarket can buy fresh lettuce for $4 a box. Each box contains 10 heads of lettuce. The lettuce is sold for $1 a head and the dealer that sells old lettuce is willing to pay $0.20 per head. Past history says that tomorrow’s demand for lettuce averages 2500 heads with a standard deviation of 750 heads. How many boxes should the supermarket purchase tomorrow?