After a rule is marked as final, no one can create a second rule with the same visible key in any ruleset other than the ruleset that the first rule belongs to. If the ruleset version of a final rule is locked, you cannot create a second rule with the same visible key in any version of any ruleset, except a higher version of the ruleset containing the final rule.
You cannot override a final rule except through a higher version in the same ruleset. Many rules in the Pega-* rulesets are marked Final because correct operation of these rules is essential to ensure the integrity and security of your system. However, most standard rules have the Availability field set to Available rather than Final; you can override those rules in your application.
Note: You cannot use circumstances or time-qualified rules to override a final rule.
Note: You can override a final rule with a sibling rule in a language-specific ruleset.
A final rule conflict arises if a rule is marked final but rules with that same name also exist in other rulesets. This rare situation can arise when rulesets are uploaded with the Import landing page tab or through other unusual means.
You can find final rules that have both the same name and other visible key parts by using the Final Conflicts report Rule-.ListThisRuleFinalCollisions.ALL. Eliminate any conflicts by deleting one of each conflicting pair until this report is empty. To access this report, select Designer Studio> Application > Inventory > Inventory Reports. Select Rule as the Category and enter "final" as the Search Text.
Some standard activities for work item processing that are marked final call empty activities that you can override. These are called extension points; they provide a natural place for you to extend the capabilities of the final rule.