Supply Chain Management, Lean System, Processes and operation
Homework Chapter 4 (SCM 488)
1. What are the 5 elements of good forecasting?
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2. Companies that are best-in-class forecasting average
____% less inventory; ____% higher order fulfillment;_____% shorter cash-to-cash cycles
3. What are the 7 basic steps to creating a forecast?
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4. What are the time horizons of short, medium and long range forecasts?
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5. During the 4 stages of product lifecycle when are qualitative and quantitative forecasts done?
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6. What is a problem forecasting with simple moving averages?
7. What is a smoothing constant and what are typical values?
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8. What is a problem with exponential smoothing forecasts?
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9. What does a season index of 120% mean?
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10. No linear correlation =___________Perfect linear correlation =__________
11. Coefficient of determination measures what?
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12. Simple Moving Average Forecast |
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Month |
Sales |
Forecast |
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1 |
3 |
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2 |
5 |
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3 |
8 |
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4 |
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13. Weighted Moving Avg. |
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60% |
most recent month |
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30% |
2 months ago |
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10% |
3 months ago |
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Month |
Sales |
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1 |
3 |
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2 |
5 |
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3 |
8 |
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4 |
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14. Exponential Smoothing |
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Week |
Demand |
Forecast (α=0.2) |
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1 |
500 |
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2 |
600 |
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3 |
400 |
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4 |
300 |
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5 |
500 |
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(β=0.4) |
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15. Exponential Smoothing with Trend |
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(α=0.2) |
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Month |
Actual |
Smoothed Forecast |
Smoothed Trend |
Forecast Including Trend |
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1 |
10 |
9 |
2 |
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2 |
20 |
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16. Season Indices |
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Month |
2001 |
2002 |
2003 |
Avg over 3 yrs |
Monthly avg |
Seasonal Index |
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Jan |
60 |
67 |
70 |
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Feb |
64 |
68 |
69 |
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March |
90 |
98 |
100 |
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April |
100 |
105 |
110 |
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May |
100 |
110 |
120 |
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17. Forecast Accuracy
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Month |
Sales |
Forecast |
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1 |
30 |
32 |
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2 |
50 |
39 |
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3 |
30 |
40 |
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4 |
20 |
32 |
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MAD = |
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Is the forecast over or underestimating? |
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MSE = |
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MAPE = |
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% accuracy = |
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18. Forecast Tracking
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Absolute |
Absolute |
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Month |
Sales |
Forecast |
Error |
RSFE |
Forecast Error |
Forecast Error |
MAD |
Tracking signal |
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1 |
30 |
32 |
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2 |
50 |
39 |
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3 |
30 |
40 |
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4 |
20 |
32 |
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