There are two general
types of rule flows: simple and complex. A simple rule flow has a
single group of rule sets. All of the rule sets are run and output
is generated for each input record.
A complex rule flow
has at least three sections: Initial, Main, and Final. Rule sets in
the Initial section are run only when the first input record is processed.
Rule sets in the Main section are run for each input record. Rule
sets in the Final section are run after the last input record has
been processed by the rule sets in the Main section.
For complex rule flows,
you can specify BY-group terms. If you
specify BY-group terms, then SAS Decision Manager sorts
the input data by those terms.
If you specify BY-group
terms, SAS Decision Manager adds two new sections to the
rule flow, Group Start and Group End. The rules sets in these sections
are run with the first and last input record in each BY group.
Note: Adding rules to any of the
sections in a complex rule flow is optional. You can leave unneeded
sections empty.