Exam 2: Forecasting demand

Define in one sentence what a time series is.

Dave is use an exponential smoothing model with trends to forecast for period 5.After gathering the data, he is trying to make a decision regarding the constants.Currently, base value smoothing constant is 0.3 and the trend smoothing constant is 0.2.What is the bias difference if Dave decides to decrease the base value smoothing constant to 0.1? The base value at the end of period 1 is 300 while the tread is -50. Period 2 3 4 Demand 700 910 1090

What is the difference between bias and MAD?

When generating the forecast for year 3 season 2 using an exponential smoothing model with seasonality, which seasonality index is subject to updating?

The annual demand of the year 2010 is provided below.Find the forecasted demand for January, 2011. Use a 3-month weighted moving average method.The weight ratio is 3:2:1 with the heaviest weight applied to the most current data. Month 1 2 3 4 5 6 7 8 9 10 11 12 Actual Demands 120 130 70 10 5 15 25 7 50 70 80 160

The conceptual forecasting framework does not exclude human judgments.When does the framework suggest these judgments should be used?

Describe the Conceptual Forecasting Framework in your own words.

The table below includes the actual demands and forecasted demand for each period.Which of the following is the correct Mean absolute deviation (MAD)value for this data? Period 1 2 3 4 5 Actual Demands 100 120 115 90 79 Forecast Demands 90 110 130 135 90

Build a forecast model using a simple exponential smoothing model with 2009 demand provided below.The exponential smoothing constant is 0.3.What is the bias for this model when the Forecast for January is set at 24? Month 1 2 3 4 5 6 7 8 9 10 11 12 Demand 17 20.4 23.8 27.2 21.6 27.6 31.2 26.35 22.95 15.3 16 14

Forecasting framework illustrates the sequences that should be followed.According to the framework, what is next step once the forecast interval is established?