CHAPTER 6
4. MURPHY MOTORS
a.
Item: P24
Week
1
2
3
4
5
6
7
8
Forecast
30
30
Orders
13
8
Available
60
30
Available to Promise
69
MPS
70
On-hand = 20, MPS lot size = 70
30
4
70
66
70
40
40
40
45
45
30
60
70
70
20
45
70
70
70
70
70
b.
Order
1
2
3
4
Amount
40
30
30
25
Desired Week
4
6
2
3
Accept (Y or N)
Y
Y
Y
Y
Updated Record
Item: P24
Week
1
2
3
4
5
6
7
8
Forecast
30
30
Orders
13
38
Available
60
22
Available to Promise
39
MPS
70
On-hand = 20, MPS lot size = 70
30
29
62
1
70
40
40
22
40
40
30
12
45
45
37
70
70
62
70
70
65
52
40
70
5. THE SPENCER OPTICS COMPANY
a.
Week
1
2
Forecast
100 100
Orders
110 80
Available
30 230
Available to Promise
30 150
MPS
300
On-hand = 140, MPS lot size = 300
3
4
5
6
7
8
9
10
100
50
130
100
20
30
100
100
100
100
100
100
230
300
300
130
30
230
300
300
130
30
3
4
5
6
7
8
9
10
0
0
b.
Week
Gross Reqs.
Sched. Receipts
Proj. Avail. Bal.
0
Plan. Order Rel.
Q = 300; LT = 2; SS = 0
1
2
0
300
300
0
300
0
300
0
0
300
0
300
0
0
6. NINO SPIRELLI
a.
Week
1
2
3
4
5
6
Forecast
20
30
Orders
14
8
Available
35
5
Available to Promise
33
MPS
50
On-hand = 5, MPS lot size = 50
20
6
35
44
50
30
20
30
5
35
50
50
55
50
50
b. No Problems.
c. He can deliver 33 immediately and 11 in week 3 or all 44 in week 3.
d.
Week
1
2
3
4
5
6
Forecast
20
30
Orders
14
8
Available
35
5
Available to Promise
33
MPS
50
On-hand = 5, MPS lot size = 50
20
6
35
29
50
30
15
5
20
30
35
50
50
55
50
50
66
7. THE CEDAR RIVER MANUFACTURING COMPANY
a.
Executive Water Pitcher
Week
1
2
3
4
5
6
7
Forecast
Orders
Available
Available to Promise
MPS
On-hand = 15, MPS lot size = 20
10
12
3
3
10
5
13
13
20
10
2
3
10
10
10
10
13
20
20
3
13
20
20
3
1
2
3
4
5
6
7
Component A
Week
Gross Requirements
Scheduled Receipts
Projected Available Balance
Planned Order Release
Q = 30, LT = 5, SS = 0
20
12
20
20
30
42
30
22
22
2
2
12
12
1
2
3
4
5
6
7
Component B
Week
Gross Requirements
Scheduled Receipts
Projected Available Balance
Planned Order Release
Q = 25, LT = 5, SS = 0
20
22
20
20
25
47
25
27
27
7
7
12
12
1
2
3
4
5
6
7
Component C
Week
Gross Requirements
Scheduled Receipts
Projected Available Balance
Planned Order Release
Q = 30, LT = 5, SS = 0
20
45
20
65
67
45
20
45
25
20
25
5
5
Component F
Week
1
Gross Requirements
Scheduled Receipts
Projected Available Balance
Planned Order Release
Q= 15, LT = 5, SS = 0
2
3
20
70
15
85
65
4
5
20
65
45
6
7
20
45
25
25
b. The due dates of the existing shop orders are invalid and should be revised as
follows:
Shop
Order
Molding
order
Component
Order
due
machine
number
item
qty.
date
time
10 - XYZ
F
*15
--2 weeks
10 - XXX
B
25
week 4
2 weeks
10 - XZV
A
30
week 2
1 week
10 - XXY
C
20
week 6
2 weeks
*This order is not needed in the current MPS and should be canceled if
possible.
Note: Molding machine time is only a portion of total lead time for each
component.
68
8. GEORGIA CLAY AND GRAVEL
a.
Smell Fresh
Week
1
2
3
4
5
6
7
8
Forecast
20
20
Orders
5
3
Available
50
30
Available to Promise
60
MPS
50
On-hand = 20, MPS lot size = 50
20
2
10
30
30
30
30
30
30
50
50
50
50
50
20
40
50
50
10
4
5
6
7
8
9
Forecast
20
20
30
30
30
30
30
Orders
13
8
20
Available
25
5
25
45
15
35
5
Available to Promise
24
30
50
50
MPS
50
50
50
On-hand = 45 = 20 period 1 on-hand + 50 MPS - 25 period 1 demand
MPS lot size = 50
40
b.
Smell Fresh
Week
2
3
69
15
50
50
9. PIKES PEAK MOUNTAIN BIKE COMPANY
Note: The current capacity is 40 hours per week.
a.
Hours
40
C
35
B
30
25
C
20
B
C
A
15
10
C
5
0
Week 1
Product
A
B
C
Product
A
B
C
Week 2
Week 1
60/10 = 6
20/5 = 4
30/15 = 2*
Week 2
50/10 = 5
15/5 = 3*
55/15 = 3.7
Week 3
Week 3
Week 1
MPS Hours
Week 2
Week 3
40
20
20
40
Week 4
Week 4
30/10 = 3
25/5 = 5*
85/15 = 5.67
Week 4
30
10
b. Pike’s Peak should decrease capacity because at the end of week 4 they have at
least 3 weeks supply of all bicycles.
c. Freezing the MPS for the next three weeks would not allow Pikes Peak to adjust to
any radical changes in demand but it would stabilize plant operations. Given the
current inventory situation it probably would not make much difference at this
time.
70
10. THE ETHAN ALLEN COMPANY
a. Priorities
Beg.
Product
Inv.
W1
W3
W2
A
20
4.00
3.00
2.00
B
50
.1.25
.25
.03
C
-30
-.86
.64* -1.43
D
25
2.50
1.50
.50
*(-30 +((35/60)  150)-35)/35
W4
1.00
1.77
.43
-.50
W5
0.00
3.50
-.57
-1.50
W6
-1.00
2.50
-1.21
7.50
W7
-2.00
1.50
.29
6.50
W8
4.50
.50
.71
5.50
Hours
35
C
B
30
A
25
20
15
C
B
B
C
10
D
B
C
C
5
0
A
Week
1
Week
2
Week
3
Week
4
Week
5
Week
6
Week
7
b. Priorities:
Beg.
Product
Inv.
W1
W3
W2
W4
W5
W6
W7
W8
A
10
2.00
1.00
0.00
-1.00
.50
7.00
6.00
5.00
B
20
.50
-.50
-.33
1.41
2.75
1.75
.75
2.09
C
32.5
.93
1.71
.71
-.29
-1.29
-.86
.64
0.00
D
0
0.00
2.33
8.00
7.00
6.00
5.00
4.00
3.00
The impact of the actual demand is to change the sequence of the first orders for
products B and D, and the order for A with C in week 5.
71
Week
8
Hours
35
A
D
30
B
25
C
20
B
15
C
10
B
D
B
B
A
5
0
C
C
Week
2
Week
3
Week
4
Week
5
Week
6
Week
7
Week
8
Week
9
c. Priorities:
Beg.
Inv.
-15
70
20
50
Product
A
B
C
D
W7
-3.00
1.75
.57
5.0
W8
3.50
.75
1.00
4.00
W9
2.50
3.09
0.00
3.00
Hours
35
30
C
B
A
25
20
15
10
B
B
D
C
B
C
C
5
0
B
A
Week
2
Week
3
Week
4
Week
5
Week
6
Week
7
Week
8
Week
9
At the beginning of week 7, A would have less and C more inventory with the frozen
schedule. The customer service levels would depend upon what actual demand occurred
during the frozen period. The factory would have more stable schedules, however.
d. The worst priority is -1, and the average priority is slightly more than one. This
means that the match between the capacity (35 hours) and the demand is just about
right. No correction is required.
72
11. XYZ COMPANY
Table A MRP Records for Item 1234
Period
1
Gross Requirements
2
438
3
4
516
Scheduled Receipts
Projected Available Balance
450
12
12
0
0
3
4
5
-64
0
0
5
6
0
0
Planned Order Release
504
Q = 2 Period Supply, LT = 2, SS = O
Period
2
Gross Requirements
580
Scheduled Receipts
504
Projected Available Balance
12
12
Planned Order Release
64
Period
3
4
Gross Requirements
207
555
Scheduled Receipts
504
64
309
-182
Projected Available Balance
12
Planned Order Release
182
73
Table B MRP Records for Item 1234
Period
1
Gross Requirements
2
438
3
4
516
Scheduled Receipts
Projected Available Balance
450
12
12
0
0
3
4
5
-64
0
0
4
5
6
Planned Order Release
504
Q = 2 Period Supply, LT = 2, SS = O
Period
2
Gross Requirements
580
Scheduled Receipts
504
Projected Available Balance
12
12
Planned Order Release
64
Period
3
Gross Requirements
580
Scheduled Receipts
504
64
-64
0
Projected Available Balance
12
Planned Order Release
182
0
0
182
a. The two period MPS freezing policy provides for a reduction in the number of
inventory shortages by 182 units) by increasing the stability of the MPS.
b. Other freezing policies that might be considered include a three period freezing
policy, and policies involving freezing the MPS in terms of the number of future
MPS orders.
c. The demand fence equals one period and the planning fences is three periods
74