Engineering Homework Help

Just questions that need answering Should be on Excel to make it easier

Questions are 12.12, 12.13, 12.14, 12.15 and 12.17 for writing questions

Then solve problems 12.1, 12.13, and 12.20

12.13. The Willow River Mining Company mines and ships coal.

It has experienced the following demand for coal during the past

eight years:

Year Coat Sales (Tons)

1 4260

2 4510

3 4050

4 3720

5 3900

6 3470

7 2890

8 3100

Develop an adjusted exponential smoothing model (α = .30, β = .20)

and a linear trend line model, and compare the forecast accuracy

of the two using MAD. Indicate which forecast seems to be most

accurate.

12.20 Temco Industries has developed a forecasting model that was

used to forecast during a ten-month period. The forecasts and actual

demand are shown as follows:

Month Actual Demand Forecast Demand

1 160 170

2 150 165

3 175 157

4 200 166

5 190 183

6 220 186

7 205 203

8 210 204

9 200 207

10 220 203

a. Measure the accuracy of the forecast using MAD, MAPD,

and cumulative error. Does the forecast method appear to be

accurate?

b. Monitor the forecast for bias using a tracking signal and a

control chart with ±3 MAD. Does there appear to be any bias in

the forecast?