# 14

# Problem #14-1:

# Given the following diagram for a product, determine the quantity of each component required to assemble one unit of the finished product.

Problem #14-2:

The following product structure tree indicates the components needed to assemble one unit of product W. Determine the quantities of each component needed to assemble 100 units of W.

Problem #14-3:

Eighty units of end item E are needed at the beginning of week 6. Three cases (30 units per case) of J have been ordered and one case is scheduled to arrive in week 3, one in week 4 and one in week 5. Note: J must be ordered by the case, and B must be produced in multiples of 120 units. There are 60 units of B and 20 units of J now on hand. Lead times are two weeks each for E and B, and one week for J.

a.prepare a material requirements plan for component J.

b.Suppose that in week 4 the quantity of E need is changed from 80 to 70. The planned order releases through week 3 have been executed. How many Bs and Js will be on hand in week 6?

Problem #14-4:

End item P is composed of three subassemblies: K, L, W. K is assembled using 3 Gs and 4 Hs. L is made of 2 Ms and 2 Ns. W is made of 3 Zs. On-hand inventories are 20 Ls, 40 Gs and 200 Hs. Scheduled receipts are 10 Ks at the start of week 3, 30 Ks at the start of week 6 and 200 Ws at the start of week 3. One hundred Ps will be shipped at the start of week 6, and another 100 at the start of week 7. Lead times are two weeks for subassemblies and one week for components G, H and M. Final assembly of P requires one week. Include an extra 10 percent scrap allowance in each planned order of G. The minimum order size for H is 200 units. Develop each of the following:

a.a product structure tree

b.a master schedule for P

c.a material requirements plan for K, G and H using lot-for-lot ordering

Problem #14-5:

Oh No!, Inc. sells three models of radar detector units. It buys the three basic models (E, F and G) from a Japanese manufacturer and adds one, two or four lights (component D) to further differentiate the models. D is bought from a domestic producer.

Lead times are one week for all items except C, which is two weeks. There are ample supplies of the basic units (E, F, and G) on hand. There are also 10 units of B, 10 units of C and 25 units of D on hand. Lot-sizing rules are lot-for-lot ordering for all items except D, which must be ordered in multiples of 100 units. There is a scheduled receipt of 100 units of D in week 1. The master scheduled calls for 40 units of A to be produced in week 4, 60 units of B in week 5 and 30 units of C in week 6. Prepare a material requirements planned for D and its parents.

* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *

# Solution #14-1:

F: 2 | G: 1 | H: 1 | ||

J: 2 x 2 = 4 | L: 1 x 2 = 2 | A: 1 x 4 = 4 | ||

D: 2 x 4 = 8 | J: 1 x 2 = 2 | D: 1 x 2 = 2 | ||

Totals: F = 2; G = 1; H = 1; J = 6; D = 10; L = 2; A = 4

# Solution #14-2:

W = 100, A=100, B=200, C=400, E=500, F=200, G=800, D=2200

# Solution #14-3a:

Master Schedule | Week | Beg. Inv. | 1 | 2 | 3 | 4 | 5 | 6 | ||

Quantity E | 80 | |||||||||

E LT = 2 wks. LFL | Beg. Inv. | 1 | 2 | 3 | 4 | 5 | 6 | |||

Gross requirements | 80 | |||||||||

Scheduled receipts | ||||||||||

Projected on hand | ||||||||||

Net requirements | 80 | |||||||||

Planned-order receipts | 80 | |||||||||

Planned-order releases | 80 | |||||||||

B(2) LT = 2 wks. 120/lot | Beg. Inv. | 1 | 2 | 3 | 4 | 5 | 6 | |||

Gross requirements | 160 | |||||||||

Scheduled receipts | ||||||||||

Projected on hand | 60 | 60 | 60 | 60 | 60 | 20 | 20 | |||

Net requirements | 100 | |||||||||

Planned-order receipts | 120 | |||||||||

Planned-order releases | 120 |

J(4xB) & J(3xE) LT = 30/lot 1 wk. | Beg. Inv. | 1 | 2 | 3 | 4 | 5 | 6 | |

Gross requirements | 480 | 240 | ||||||

Scheduled receipts | 30 | 30 | 30 | |||||

Projected on hand | 20 | 20 | 20 | 50 | 80 | 50 | 50 | |

Net requirements | 460 | 160 | ||||||

Planned-order receipts | 480 | 180 | ||||||

Planned-order releases | 480 | 180 |

Master Schedule | Week | Beg. Inv. | 1 | 2 | 3 | 4 | 5 | 6 | ||

Quantity E | 70 | |||||||||

E LT = 2 wks. Lot: LFL | Beg. Inv. | 1 | 2 | 3 | 4 | 5 | 6 | |||

Gross requirements | 70 | |||||||||

Scheduled receipts | ||||||||||

Projected on hand | ||||||||||

Net requirements | 70 | |||||||||

Planned-order receipts | 70 | |||||||||

Planned-order releases | 70 | |||||||||

B(2) LT = 2 wks. 120/lot | Beg. Inv. | 1 | 2 | 3 | 4 | 5 | 6 | |||

Gross requirements | 140 | |||||||||

Scheduled receipts | ||||||||||

Projected on hand | 60 | 60 | 60 | 60 | 60 | 40 | 40 | |||

Net requirements | 80 | |||||||||

Planned-order receipts | 120 | |||||||||

Planned-order releases | 120 |

J(4xB) & J(3xE) LT = 30/lot 1 wk. | Beg. Inv. | 1 | 2 | 3 | 4 | 5 | 6 | |

Gross requirements | 480 | 210 | ||||||

Scheduled receipts | 30 | 30 | 30 | |||||

Projected on hand | 20 | 20 | 20 | 50 | 80 | 80 | 80 | |

Net requirements | 460 | 130 | ||||||

Planned-order receipts | 480 | 150 | ||||||

Planned-order releases | 480 | 180 |

There will be 40 units of B and 80 units of J.

# Solution #14-4:

a. Product Structure Tree

b.

Master Schedule | Weeks | Beg. Inv. | 1 | 2 | 3 | 4 | 5 | 6 | 7 | |

Quantity | 100 | 100 | ||||||||

c. | P LT = 1 wk. Lot: LFL | Beg. Inv. | 1 | 2 | 3 | 4 | 5 | 6 | 7 | |

Gross requirements | 100 | 100 | ||||||||

Scheduled receipts | ||||||||||

Projected on hand | ||||||||||

Net requirements | 100 | 100 | ||||||||

Planned-order receipts | 100 | 100 | ||||||||

Planned-order releases | 100 | 100 | ||||||||

K LT = 2 wk. Lot: LFL | Beg. Inv. | 1 | 2 | 3 | 4 | 5 | 6 | 7 | ||

Gross requirements | 100 | 100 | ||||||||

Scheduled receipts | 10 | 30 | ||||||||

Projected on hand | 10 | 10 | 10 | |||||||

Net requirements | 90 | 70 | ||||||||

Planned-order receipts | 90 | 70 | ||||||||

Planned-order releases | 90 | 70 | ||||||||

G(3) LT = 1 wk. Lot: LFL | Beg. Inv. | 1 | 2 | 3 | 4 | 5 | 6 | 7 | ||

Gross requirements | 270 | 210 | ||||||||

Scheduled receipts | ||||||||||

Projected on hand | 40 | 40 | 40 | 40 | ||||||

Net requirements | 230 | 210 | ||||||||

Planned-order receipts | 253 | 231 | ||||||||

Planned-order releases | 253 | 231 | ||||||||

H(4) LT = 1 wk. Lot: 200 units min | Beg. Inv. | 1 | 2 | 3 | 4 | 5 | 6 | 7 | ||

Gross requirements | 360 | 280 | ||||||||

Scheduled receipts | ||||||||||

Projected on hand | 200 | 200 | 200 | 200 | 40 | |||||

Net requirements | 160 | 240 | ||||||||

Planned-order receipts | 200 | 240 | ||||||||

Planned-order releases | 200 | 240 |

# Solution #14-5:

Master Schedule | Week | Beg. Inv. | 1 | 2 | 3 | 4 | 5 | 6 | |

Quantity | 40A | 60B | 30C | ||||||

A LT = 1 wk. | Beg. Inv. | 1 | 2 | 3 | 4 | 5 | 6 | ||

Gross requirements | 40 | ||||||||

Scheduled receipts | |||||||||

Projected on hand | |||||||||

Net requirements | 40 | ||||||||

Planned order receipt | 40 | ||||||||

Planned order release | 40 | ||||||||

B LT = 1 wk. | Beg. Inv. | 1 | 2 | 3 | 4 | 5 | 6 | ||

Gross requirements | 60 | ||||||||

Scheduled receipts | |||||||||

Projected on hand | 10 | 10 | 10 | 10 | 10 | 10 | |||

Net requirements | 50 | ||||||||

Planned order receipt | 50 | ||||||||

Planned order release | 50 | ||||||||

C LT = 2 wks. | Beg. Inv. | 1 | 2 | 3 | 4 | 5 | 6 | ||

Gross requirements | 30 | ||||||||

Scheduled receipts | |||||||||

Projected on hand | 10 | 10 | 10 | 10 | 10 | 10 | 10 | ||

Net requirements | 20 | ||||||||

Planned order receipt | 20 | ||||||||

Planned order release | 20 | ||||||||

D LT = 1 wk. | Beg. Inv. | 1 | 2 | 3 | 4 | 5 | 6 | ||

Gross requirements | 40 | 180 | |||||||

Scheduled receipts | 100 | ||||||||

Projected on hand | 25 | 125 | 125 | 125 | 85 | 5 | |||

Net requirements | 95 | ||||||||

Planned order receipt | 100 | ||||||||

Planned order release | 100 |