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

Solution #14-3b:

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