Aggregation options in the formula editor

The Aggregation Options setting indicates whether a variable is linear (that is, the values for individual projects or analogues can be summed to give the total), or if the result must be calculated at the project level (for analogues) or group level (for grouped projects). For example, given a function 'Result = X / Y' for three projects P1, P2 and P3, the aggregated result for the group (Result_Group) will be determined as follows:

• Calculate by summing up results (this is incorrect for a ratio):

  Result_Group = X_P1 / Y_P1 + X_P2 / Y_P2 + X_P3 / Y_P3

• Calculate at group level by summing inputs:

  Result_Group = (X_P1 + X_P2 + X_P3) / (Y_P1 + Y_P2 + Y_P3)

When the Results By option is active, the following aggregation options become available in its drop-down menu. The options that appear depend on the type of data you are working with, and are listed in the table below.

Data Type	Aggregation options
Double	Sum
Boolean	Logical AND excludes any values containing a FALSE or 0 result. Logical OR excludes values containing only FALSE or 0 results.
DateTime	Earliest shows the earliest result. Latest shows the latest result. Most Frequent shows the most frequently occurring result.
String	Common: All data with the specified string will appear with that string in results; data with other strings will display a dash in that field.

If you are calculating a rate, such as a production rate over a period of time, you should choose Input in the Aggregation Options. For any other type of calculation, aggregating by Input or Results By will produce the same result.