Solved Problems • Chapter 13  1

Solved Problems

Chapter 13: planning for material and resource requirements

  1. Southern Electronics manufactures disk drive controller cards for personal computers. To meet demand, the company's aggregate production plan calls for 4,000 cards to be manufactured during January and 5,000 during February. In the past, 200-gigabyte (Gb) controller cards have made up 40 percent of the total demand for controller cards. Demand for these cards is expected to be uniform throughout each month.

If 500 of the 200-Gb controller cards are in inventory at the end of December and customer orders booked are as shown below, determine the master schedule and the available-to-promise quantities for each month. Southern prefers to produce 200-Gb controller cards in batches of 1,000.

January / February
1 / 2 / 3 / 4 / 5 / 6 / 7 / 8
Customer orders booked / 500 / 350 / 400 / 350 / 300 / 300 / 250 / 200

Based on historical accounting data, each 200-Gb card requires 4.2 standard hours to produce. Thirty percent of all standard hours are used by the wave soldering machine. Based on the master schedule established in part a, estimate capacity requirements for wave soldering each week to produce the 200-Gb controller cards.

SOLUTION

  1. If 40 percent of controller card demand is for 200-Gb cards, then 1,600 will be demanded during January and 2,000 during February. Assuming uniform demand, 400 will be demanded each week in January and 500 each week in February. The table in Exhibit 13.27 may be completed.

EXHIBIT 13.27

Each 200-Gb card requires 4.2 standard hours, and if 30 percent is used by the wave soldering machine, then requirements for each board will be .30(4.2) = 1.26 standard hours. Based on the master schedule, the requirements for wave soldering of 200-Gb cards will be

WEEK
1 / 2 / 3 / 4 / 5 / 6 / 7 / 8
Standard hours / 0 / 1,260 / 0 / 1,260 / 0 / 1,260 / 0 / 1,260
  1. The Arctic Snow Shovel Company manufactures aluminum snow shovels that have the following bill of materials:

Level / Item / Quantity Required
0 / Aluminum snow shovel / 1
1 / Blade assembly / 1
2 / Blade / 1
3 / Aluminum sheet / 1.5 ft.
2 / Blade plate / 1
2 / Rivets / 10
2 / Handle connector / 1
1 / Handle assembly / 1
2 / 1.5" diameter wooden shaft / 3 ft.
2 / Plastic handle / 1
2 / 1" flat-head wood screws / 4

Arctic currently has no blade assemblies on hand. The production lead time for making blade assemblies is one week, and they may be produced in any quantity. There are 100 blades in stock and another 1,000 in production, due to be completed next week. Lead time is also one week for blades, which are produced in batches of 1,000. The aluminum sheet for these blades is ordered in quantities of 10,000 feet, and there are currently 2,000 feet in stock. The lead time for ordering aluminum sheet is two weeks.

Based on the preceding information and the following master schedule showing planned production for snow shovels during the next six weeks (it is currently week 27), determine planned orders for aluminum sheet:

Master Schedule - Aluminum Snow Shovels
Week
28 / 29 / 30 / 31 / 32 / 33
500 / 400 / 600 / 600 / 400 / 400

SOLUTION

Because aluminum sheet is a component of blades, which are in turn a component of blade assemblies, we must perform MRP for all three items, as shown in Exhibit 13.28, illustrating the MRP for aluminum snow shovels.

EXHIBIT 13.28

  1. The Discount Club, a retailer located in Atlanta, operates wholesale warehouse stores throughout the Southeast. The company maintains a distribution center in Atlanta and warehouses in Norfolk and Tallahassee. One item the company sells is motor oil, which is bought in bulk barrel quantities through the Atlanta distribution center. Given the information in Exhibit 13.29, calculate planned order releases from the Atlanta distribution center if shipments to the warehouses are in 500-barrel quantities and shipments to the distribution center are in 2,000-barrel quantities. The lead time for shipments to the warehouses is one week and for shipments to the distribution center is two weeks.

EXHIBIT 13.29

SOLUTION

The results are shown in Exhibit 13.30.

EXHIBIT 13.50

Vonderembse and White • Operations Management