At this stage you have 4 measures configured and deployed in your Flow System. However, these measures only collect or calculate summary information for every hour. What if you wanted to summarize and report information for daily time periods?
As discussed on page 45, Aggregated Measures are used to perform roll up calculations of other measures in your Flow System. Let’s use an Aggregated Measure to roll up the hourly summary information into daily information.
Drag the “Steam Production Rating (tons/hr)” measure from the Model View onto the “Daily” icon of the Flow Zone.
Flow will create a new daily “Steam Production Rating (tons/hr)” measure. Notice the icon indicates the Interval (i.e. daily) and the Measure Type (i.e. aggregated Δ).
Double-click the new measure and notice the general properties have been copied from the hourly “Steam Production Rating (tons/hr)” measure. Because this is a daily measure, change the “Unit” to “tons/day” as follows:
Expand the “Retrieval” section. Notice that the “Retrieval” section is different for an Aggregated Measure.
- Measure – this is the measure Flow will roll up (i.e. aggregate) to create new summary information. To change this measure, drag another measure from the Model View onto this setting.
- Aggregation – 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”, “First”, “Last” and “Counter”.
- Interval – 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.)
Deploy the new measure and confirm that it is running and producing a value of 348.0 tons every day:
Now create daily Aggregated Measures for “Steam Production (tons/day)” and “Steam Temperature (˚C)”. For the daily “Steam Temperature (˚C)”, make sure you change the “Aggregation” property to “Average”, not “Sum”. It would not make sense to sum the hourly average temperature summaries!