Review #3

  1. The MRP input stating which end items are to be produced, when they are needed, and what quantities are needed, is the:
  2. master schedule
  3. bill-of-materials file
  4. inventory record file
  5. assembly-time chart
  6. net-requirement chart
  1. In an MRP master schedule, the planning horizon is often separated into a series of times periods called:
  1. pegs
  2. lead time
  3. stacked lead time
  4. time buckets
  5. non of the above
  1. The MRP input storing information on the status of each item by time period (e.g., scheduled receipts, lead time, lot size) is the:
  1. master production schedule
  2. bill-of-materials file
  3. inventory record file
  4. assembly-time chart
  5. net-requirement chart
  1. Which one of the following most closely describes net requirements?
  1. Gross requirements – amount on-hand – scheduled receipts
  2. Gross requirements – planned receipts
  3. Gross requirements 0 order releases + amount on-hand
  4. Gross requirements – planned order release
  5. Gross requirements – amount on-hand + planned order releases
  1. In MRP, “scheduled receipts” are:
  1. identical to “planned order receipts”
  2. identical to “planned order releases”
  3. open orders (that is, ordered before the first time bucket but not delivered yet)
  4. “net requirements”
  5. none of the above
  1. A basic requirement for operating with low inventories in JIT systems is
  1. inventory space must be saved
  2. inventory investment must be saved
  3. major problems must be uncovered
  4. major problems must have been solved
  5. inventory must be reduced rapidly

7. Which of the following statements about ERP is true?

a). ERP is limited to operations internal to the enterprise

b). ERP is similar to MRPII, except that t extends to service operations.

c). ERP allows customers to access the system

d). Both ERP and MRPII are linked to the external supply chains.

8. Which of the following statements about lot-sizing rules for MRP is true?

a). The POQ rule generates a high level of average inventory

b). FOQ reduces the amount of inventory on hand

c). the L-4-L rules minimize inventory investment, but increases the number of orders

d). all lot-sizing rules seek to minimize inventory levels.

9. The available-to-promise quantity for the first period of an MPS is equal to: current on-hand inventory, minus the cumulative total of booked customer orders up to the period in which the next MPS quantity arrives, plus

a). the forecast for the first period

b). the MPS quantity for the first period, if any

c). the projected n-hand inventory for the first period

d). the cumulative total of forecasts for all periods in the future

10. Which one of the following is an advantage of JIT?

a). JIT systems reduce equipment needs by using larger lot sizes

b). JIT systems result in an increase in manufacturing lead time

c). JIT systems result in a decrease in safety stock and WIP inventory

d). JIT systems reduce WIP inventory by adopting a push system

Sample problems: MPS and MRP

1. Using the information in the following table, prepare a prospective MPS and calculate the available-to-promise (ATP) quantities on the table below. The order policy is to produce in lots of 150.

Week
Quantity on hand: 60 / 1 / 2 / 3 / 4 / 5 / 6 / 7 / 8
Forecast / 50 / 50 / 50 / 50 / 60 / 60 / 60 / 60
Customer orders (booked) / 20 / 95 / 110 / 35 / 30 / 55 / 20 / 0
Projected on-hand inventory
MPS quantity
Available-to-promise (ATP)

The earliest time that a new customer order of 100 units can be delivered is in?

a)Week 1

b)Week 2

c)Week 3

d)Week 4

2. Use the following MPS, BOM, and inventory data, fill out the MRP tables provided in the next page to answer questions 1 to 3.

a) Master Production Schedule: The following table shows the MPS release dates already offset for item A's lead time.

Week
Week / 1 / 2 / 3 / 4 / 5 / 6
MPS / 60 / 70 / 40

b) Bill of Material

-End item A uses 1 each of component D and 2 each of subassembly C.

-Subassembly C uses 2 each of component E.

c) Selected Inventory Data

Item
Data Category / C / D / E
Lot-sizing rule / FOQ=50 / L4L / POQ (P=2)
Lead time (weeks) / 1 / 1 / 1
Beginning (on-hand) inventory / 30 / 0 / 30
Safety stock / 0 / 0 / 20
Scheduled receipts / 50 (wk 1) / 30 (wk 1) / 90 (wk 1)
  1. What is the largest quantity of projected on-hand inventory for any of the weeks for item D?
  1. 0 units
  2. greater than 0, but less than or equal to 25 units
  3. greater than 25, but less than or equal to 50 units.
  4. Greater than 50
  1. How many planned order releases are there for item C?
  1. none
  2. one
  3. two
  4. more than two
  1. Which of the following statements concerning item E is true?
  2. The projected on-hand inventory quantity in week 4 is 0 units
  3. The planned order receipt in week 3 is 100 units
  4. There is exactly one action notice needed
  5. There are planned order receipts needed in weeks 3 and 5.

MRP tables

Item:

Lead time:

Lot size:

1 / 2 / 3 / 4 / 5 / 6 / 7 / 8
Gross requirements
Scheduled receipts
On-hand Inv.
Planned receipts
Planned releases

Item:

Lead time:

Lot size:

1 / 2 / 3 / 4 / 5 / 6 / 7 / 8
Gross requirements
Scheduled receipts
On-hand Inv.
Planned receipts
Planned releases

Item:

Lead time:

Lot size:

1 / 2 / 3 / 4 / 5 / 6 / 7 / 8
Gross requirements
Scheduled receipts
On-hand Inv.
Planned receipts
Planned releases