Additive and nonadditive data

Rational ProjectConsole Designer Help

Additive data is data collected incrementally. An example of additive data is the number of lines changed measure that is collected in the sample Webshop Rational ClearCase Collection task. Every time you run this collection, you collect the number of lines changed since the last data collection so the collected data does not overlap. If you create a trend chart showing the number of lines changed by month, you want to see the total number of lines changed during that month, so the chart needs to add the data collected by every task run during that month.

Nonadditive data is data collected every time a collection runs. An example of this is a Rational ClearQuest collection task that collects the state of defects. Every time you run this collection, you collect the same defects with their updated state. If you create a trend chart that shows the number of defects in a given state by week, you want to see the number of defects in each state reported by the last collection run during that week, and not the addition of the defects in that state collected by each collection run during that week.

For more information about additive and nonadditive data, see Field Information window.