You may not use a calculator on this exam. You are allowed one index card of notes, 3 inches by 5 inches.

Transcription

1 ISyE 6335, Exam 2, 24 October 2017 Time Limit: 45 minutes Name: This exam contains 6 pages (including this cover page) and 5 problems. Check to see if any pages are missing. Enter all requested information on the top of this page, and put your initials on the top of every page, in case the pages become separated. You may not use a calculator on this exam. You are allowed one index card of notes, 3 inches by 5 inches. To receive credit, your work must be justified, legible, comprehensible and your own. signing your name above you agree to abide by the Georgia Tech honor code. By If you need more space, use the back of the pages; clearly indicate when you have done this. Do not write in the table below. Question: Total Points: Score:

2 ISyE 6335 Exam 2 - Page 2 of 6 24 October (8 points) A forward pick area to support case-picking from pallets (a) (2 points) To avoid stockouts in the forward pick area, should a SKU be allocated more pallets or more pallet locations? Solution: Pallets (b) (2 points) To reduce the chance of congestion in the forward pick area, should a SKU be allocated more pallets or more pallet locations? Solution: Pallet locations (c) (2 points) What are the units-of-measure for bang-for-buck for a SKU that is considered for forward storage in a forward case-pick-from-pallet area? Solution: Person-hours per pallet location, or, more generally, time per unit of space. (d) (2 points) Which of the following should be included in the cost of restocking a forward case-pick area? 1. Travel between the forward area and the bulk storage area 2. Time to travel vertically to retrieve the pallet 3. Time to scan the storage location and pallet to confirm product 4. Time to insert the pallet into the forward pick location 5. Time to remove the shrink-wrap from the pallet so that cases can be picked Solution: All but the last, because they are incurred only to perform the restock, and so they are variable costs with respect to the decision of where to pick the SKU. The last one is a fixed cost that will be incurred wherever the pallet is located.

3 ISyE 6335 Exam 2 - Page 3 of 6 24 October (11 points) A forward pick area to support case-picking from pallets (a) (5 points) To save time, a forward pick should not exceed what fraction of a pallet? Solution: Let s be the savings per pick and c r the cost per restock of a forward pick area. Let x represent the fraction of a pallet taken in one pick. To be positive, the net benefit of this pick must satisfy s 1 c r x > 0, or x < s/c r (b) (2 points) Consider a SKU that is picked as cartons from pallets. Up to now it was packaged by the vendor as 36 cartons per pallet but has recently been repackaged as a taller pallet of 48 cartons. How does this affect its suitability for space in the forward-pick area and why? Solution: It has increased because fewer restocks will be required (in fact, only 36/48 = 3/4 as many) and so its bang-for-buck will increase. (c) (2 points) Who primarily determines the number of restocks to a forward pick area where pieces are picked from cases? (The customer? Warehouse management? Both? Neither?) NB: This question is out of place and should have appeared as 4c, but answer it here as written. Solution: Both; the number of restocks for each SKU depends on both the flow, which is determined by quantities customers purchase, and the volume stored in the forward area, which is determined by warehouse management. (d) (2 points) What are the dimensions (units) of the bang-for-buck for picking cases from pallets? Solution: Time per unit of space (e.g. person-hours per cubic meter or person-hours per pallet location)

4 ISyE 6335 Exam 2 - Page 4 of 6 24 October (12 points) Forward pick area for small parts: Choose one of the following to answer each of questions (a) (f) regarding a forward piece-pick area. 1. SKU with greatest bang-for-buck 2. SKU with most picks 3. SKU with greatest value of flow 4. SKU with greatest value of picks per unit of flow 5. SKU with the greatest value of flow per pick 6. SKU with most picks per restock 7. SKU with most picks per volume of allocated space (a) (2 points) Among all SKUs which has strongest claim to forward storage? Solution: The SKU with the greatest bang-for-buck (b) (2 points) Among the forward SKUs, which will be receive the most space, if allocations are chosen to minimize the number of restocks? (c) (2 points) Among the forward SKUs, which will receive the most space, if Equal Time allocations are used? (d) (2 points) Among the forward SKUs, which will be restocked most frequently, if allocations are chosen to minimize the number of restocks? (e) (2 points) Among the forward SKUs, which will be restocked most frequently, if space is allocated equally? (f) (2 points) Among the forward SKUs, which should be in the golden zone? Solution: The SKU with the greatest pick-density (picks per volume of allocated space)

5 ISyE 6335 Exam 2 - Page 5 of 6 24 October (9 points) A forward pick area to support piece-picking from cases (a) (2 points) Suppose that a SKU in the forward area has been repackaged by the vendor into larger cases that hold 200 pieces, rather than the 150 pieces that the previous, smaller cases held. How does this affect the suitability of this SKU for forward storage? 1. The bang-for-buck decreases. 2. The bang-for-buck remains the same. 3. The bang-for-buck increases. 4. It is impossible to tell. Solution: Since this SKU is restocked in case quantities, not pallets, this re-packaging has no significant effect on the number of restocks and so the bang-for-buck of this SKU is unchanged. Credit will be given if you said there would be a slight reduction in the cost of restocking due to would be fewer cases to open for the same level of sales, and hence a slight increase in the bang-for-buck. (b) (3 points) Say whether each of the following is true or false. 1. Our model of a forward pick area assumes an arbitrarily large reserve or bulk storage. 2. Our model of a forward pick area assumes that the rate of picking achievable in the forward pick area is independent of which SKUs are stored there. 3. Our model of a forward pick area assumes that each SKU perfectly fills the space allocated to it. Solution: All true (c) (2 points) Who primarily determines the number of restocks to a forward pick area where cases are picked from pallets? (The customer? Warehouse management? Both? Neither?) NB: This question is actually out of place. It should have appeared as question 2c, but answer it here as written. Solution: The customer, because the total quantity purchased of each SKU, measured in pallets, is the number of restocks for that SKU. (d) (2 points) What are the dimensions (units) of the bang-for-buck for picking pieces from cartons? Solution: Time per unit of space

6 ISyE 6335 Exam 2 - Page 6 of 6 24 October (5 points) How can you measure the value of a given quantity of forward space? Solution: Compute the total net benefit resulting from choosing the best SKUs to store there.