HP 3000 Manuals HP 3000 Manuals
Trending Method Option The Trending Method option appears on the Forecasts command dialog box. Use this option to determine which trending method HP RXForecast will use to model. Choose the method based on the way you expect your data to change over time.Smoothing The Smoothing method does not forecast at all. Instead, it displays the trend over time. The method itself is called median smoothing. It replaces the values with medians of surrounding values until a smooth curve is obtained. No Interval Types option is available with this technique. Linear The Linear method is the most common and simplest method for trending. It models the trend as a straight line. Exponential The Exponential method is similar to the Linear method. The trend, however, is projected using an exponentially increasing function. This may be applicable in the case of response times that tend to increase slowly when the load is light, but quickly when the load is heavy. S-Curve The S-Curve method is another function that can be used in certain situations. If the metric has the same behavior as the exponential function except that it levels off at some value, this method may be useful. For example, CPU Utilization may start off stable at a certain value, but increase rapidly until about 90 percent and then level off; slowly approaching, but never exceeding, 100 percent. Business Units In the Business Units method, a trend is correlated to a known business unit that the user constructs. Two kinds of information are necessary to build a business unit: * Historic data on the business unit. * Future values forecasted for the business unit. In order to forecast past the last date in the logfile, you must forecast the business unit into the future and include those values in the business unit file. Typically, this forecast would be derived from a business plan or projections made by a planning group. In short, you need to know where the business unit has been and where it is likely to go. Once you have the necessary information on the business unit, you can construct a business unit file by entering the business units and applicable dates into a flat ASCII file. See "Creating a Business Unit File" . In order to use the Business Units trending method, you must correlate a trend to a known, user-defined business unit. Selection of a business unit should be based on factors that affect the specific computer system. A good business unit has strong correlation with the metric being forecast. The Business Units trending method is most successful when such a correlation exists. The Business Units trending method is dimmed (cannot be selected) until a business unit file has been selected on the NEXT screen.
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