The GRC 10 application makes use of BRF+ tool to create rules which are used to customize agents, initiators, detours, hr trigger, etc.
Specifically talking about the HR trigger rules, there are certain values that can be maintained in the decision table of the HR Trigger BRF+ rule, in order to capture the employee changes performed via HR transaction PA40.
Below is an example/suggestion of a decision table conditions for: New Hire (CRE), Terminitation (TER) and Position Change (CHN)