Materials Mgmt- Zeek the Geek
MGMT 4317 Chapter 8 Homework Problems – You must show all work in all problems to receive credit. You will receive zero (0) credit for providing the answer only.
1. Demand over past 3 months has been 250, 210, and 224 units. Using a three-month moving average, determine the forecast for month four. If the actual demand in month 4 is 264, calculate the forecast for month 5.
2. Given the following data, calculate the three-month moving average forecasts for months 4, 5, 6, and 7.
Month
Actual Demand
Forecast
1
65
2
80
3
50
4
45
5
60
6
70
7
3. If the forecast for May was 222, and the actual demand for May is 235, what would be the forecast for June if the smoothing constant (alpha) is .20? If June demand is actually 290, calculate forecast for July.
4. Given the following average demand, calculate the seasonal indices for each quarter:
Quarter
Average Demand
Seasonal Index
1
164
2
480
3
490
4
170
Total
Note that your answer, if calculated correctly, should have all of the seasonal indices add up to the number of quarters in the entire season.
5. Using the data in problem 4, and the seasonal indices you have calculated, calculate expected quarterly demand if the annual forecast is 2000 units.
Quarter
Seasonal Index
Forecast
1
2
3
4
6. Calculate the deseasonalized demands for the following:
Quarter
Annual Demand
Seasonal Index
Deseasonalized Demand
1
130
0.70
2
170
1.00
3
375
1.80
4
90
0.50
Total
7. For the following data, calculate the mean absolute deviation (MAD).
Period
Forecast
Actual Demand
Absolute Deviation
1
100
80
2
100
110
3
100
130
4
100
75
5
100
105
Total
8. A company uses a tracking signal trigger of + or – 4 to decide whether a forecast should be reviewed. Given the following history, determine in which period the forecast should be reviewed. Mean Absolute Deviation (MAD) for the item is 15. Is there any previous indication that the forecast should be reviewed?
Period
Forecast
Actual
Deviation
Cumulative Deviation
Tracking Signal
1
100
110
2
105
90
3
110
85
4
115
110
5
120
105
6
125
95
