HP 3000 Manuals

HP RXForecast Users Manual for MPE Systems

Trying Trending Methods 

Next you will look at the S-Curve and Exponential trending methods.
Business Units is a special case that is explained in Chapter 4 .

In preparation for producing the graphs in this section, do the following
on the RXForecast Options command dialog box:

   1.  Change the Interval Type to None.

   2.  Verify that every Seasonality Level is enabled (checked).

   3.  Click on  OK.

S-Curve 

Follow the steps below to draw a forecast using the S-Curve trending
method.  On the Forecasts command dialog box, do the following:

   1.  Change the trending method to S-Curve.

   2.  Leave all other options the same.

   3.  Click on  OK.

You will see the following forecast:


            

An S-Curve can be very difficult to see because you have to see all of
the curve to detect its shape.  Any part of the curve alone may look like
another trend type.  For instance, the beginning and end of an S-Curve
may look linear, while the middle looks exponential (that is, has an
increasing or decreasing slope).  CPU Utilization can exhibit this trend
because it is bounded above and below (you cannot have CPU Utilization
greater than 100 percent or less than 0 percent).

Close the graph.

Exponential 

Metrics that are not bounded above often seem exponential.  Response time
is just such a metric.  It looks exponential, but tends to become linear
again as it grows.

Make the following selections to see an exponential curve:

   1.  Choose First Response on the Forecasts command dialog box.

   2.  Change the Trending Method to Exponential.

   3.  Leave all other options as they are.

   4.  Click on  OK.


            

Close the graph.

MPE/iX 5.0 Documentation