Field help (AWRSYNFLD) 

This field is entered when the field used as criterion is located in a table linked to the model main table a with a (1,N) link.

In this case, the value obtained for the criterion corresponds to the aggregation of a group of lines, and the operator entered here is used to specify the calculation method.

The Sum and Average aggregation operators can only be used if the criterion is a numerical one. The Minimum and Maximum operators can be used in all cases.