You can use rules in the context of a business process in two ways as follows:Rules Service
Model your rules in the rules composer.
More Information: Modeling Rules with the Rules Composer
Use the rules service through an automated activity.
More Information: Modeling Automated Activities
Create a ruleset in the process composer.
Use the ruleset like any other function in the process composer. For example, you can use a ruleset as a transform in a mapping activity.
If the ruleset function has a boolean return type, it can be used as a gateway condition.
More Information: Controlling the Process Flow with Gateways
Modeling Rules with the Process Composer
You perform the following tasks to model rules in the process composer: