1. Jill did not consider combining the forecasts generated by the two methods she analyzed. How would she go about doing so? What would be the advantages and disadvantages of such action?
2. The optimum smoothing constants used by Holt's linear exponential smoothing were α = 1.77 and β = .14. As new data come in over the next few quarters, Jill should probably rerun her data to see if these values change. How often do you think she should do this?
3. It's possible that the choice of forecasting method could shift to another technique as new quarterly data are added to the database. Should Jill rerun her entire analysis once in a while to check this? If so, how often should she do this?
4. A colleague of Jill's suggested she try the Box-Jenkins ARIMA methodology. What advice do you have for Jill if she decides to try Box-Jenkins? Can you identify a tentative ARIMA model?
Jill Tilly was a recent graduate of a university business school when she took a job with Busby Associates, a large exporter of farm equipment. Busby's president noticed a forecasting course on Jill's resume during the hiring process and decided to start Jill's employment with a forecasting project that had been discussed many times by Busby's top managers.