FO RE CAST ING
Figure 3: Initial daily domestic box-office gross of the motion picture (“Non-Stop”).
March 16, or 17 days of data. The students were asked to make a time plot
of these box-office figures (see Figure
3) and, after examining various trend
models, get a forecast for the cumulative domestic box-office gross for a
target date, midterm day, March 31.
I knew that two days later (after I had
graded their exams and returned them),
Universal Studios would give the actual
cumulative domestic gross of the film
as of March 31. It was $85.39 million.
Of the various trend models we covered, the Weibull curve yielded the most
accurate forecast, $86.11 million; another model was reasonably close, and the
others we discussed and they tried were
way off.
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A N A LY T I C S - M A G A Z I N E . O R G
CATEGORIZING THE FORECAST
SOFTWARE
Commercial forecasting software
is available in two broad categories.
Using the nomenclature from previous
OR/MS Today forecasting surveys, the first
category is called dedicated software. A
dedicated product implies that the software
only has various forecasting capabilities,
such as Box-Jenkins, exponential smoothing, trend analysis, regression and other
procedures. The second category is called
general statistical software. This implies the
product does have forecasting techniques
as a subset of the many statistical procedures it can do. Thus, a product that can
do ANOVA, factor analysis, etc., as well
as Box-Jenkins techniques would fall into
W W W. I N F O R M S . O R G