Aggregated Measures are used to perform roll-up calculations of other measures in your Flow System.
For example, you may have already created a measure that summarizes the Boiler Temperature from a Data Source every hour. You can configure a new Aggregated Measure to calculate the daily average of these hourly values.
This means that the new daily measure does not have to re-query the detailed data from the Data Source to provide the daily summary values, it rather uses the information Flow has already collected from the Data Source for the hourly values.
Furthermore, if any of the hourly values need to be edited via the Flow Server, Flow will automatically re-calculate the daily Aggregated Measure, thus maintaining the integrity of the information stored in your Flow System.
To configure an Aggregated Measure, change the Retrieval Type combobox in the Retrieval section of the Measure Editor to "Aggregated from another Measure". Alternatively, a quick way to create an Aggregated Measure is to drag a measure onto an Interval Type in the Flow Zone.
Notice the Retrieval section properties for an Aggregated Measure:
||This is the measure/event that Flow will roll up (i.e. aggregate) to create new summary information. To change this source, drag another measure (or an event) from the Model View onto this textbox.|
||This is the aggregation method Flow will use to calculate the roll up. Flow will default to “Sum”, but available aggregation methods include “Average”, “Minimum”, “Maximum”, “Range”, "Delta", “First”, “Last” and “Counter”.|
||This is the “boundary” interval Flow will use to calculate the roll up summary information. This property can be changed when cumulative roll up calculation are required (e.g. “Week to Date”, or “Month to Date”, etc.)|
||This is a multiplier applied to the result of the aggregation. This is useful when you need to present an aggregated value in a different Unit of Measure (e.g. the hourly measure can be kWh, but the monthly aggregated value should be in MWh).|