Management's action to recoup the duplicate payments made to a vendor is an effect-based action plan because it directly addresses the outcome (the duplicate payment) rather than the underlying cause that allowed the error to occur. An effect-based action plan focuses on correcting the issue's immediate consequences but does not necessarily address the root cause that led to the issue in the first place.
IIA Reference:
IIA Standard 2500: Monitoring Progress emphasizes that internal auditors should monitor the disposition of audit recommendations. Addressing only the effects of an issue, like in this case, might provide a temporary fix but does not prevent future occurrences if the underlying causes are not identified and corrected.