HP 3000 Manuals

HP RXForecast Users Manual for MPE Systems

Validating 

Once you have produced a forecast, you will want to check its validity.
That is, you will want to confirm that it reasonably represents the
system it was designed to represent.  In this section, you will take a
quick look at just one way of validating a forecast:  the Validate date
option.

On the Forecasts command dialog box, do the following:

   1.  Select Job CPU.

   2.  Select Linear for the Trending Method.

   3.  Select an X-Axis of 6 months.

   4.  Set Dates as follows to use the validate feature:

          a.  Set Start date at Start.

          b.  Set Stop date at April 29.

          c.  Leave the Validate date at Last.

   5.  Click on  OK.

You will see the following graph:


            

Ignore the validate line for a moment.  Instead, look at the data line,
which spans March 1 to April 29.  Notice that the trend line begins at
the beginning of May and continues through the end of August.  If you
went back in time to April 29 and drew a forecast using the linear
trending method, this trend line (forecast) is what you would get.

Now look at the validate line.  It shows what really happened to Job CPU
over those 4 months.  You can see that the forecast differs dramatically
from actuality.  This means that your forecast is not valid (linear is
not a valid trending method).

You can see how critical it is to validate your forecast whenever
possible.  You can also see how useful it is to have long-term logfiles.

Validate date and other methods of validation are discussed in detail in
"Validating a Forecast" .

Close the graph.

MPE/iX 5.0 Documentation