If testing the operating effectiveness of controls surrounding an estimate alone does not provide sufficient appropriate audit evidence,

If testing the operating effectiveness of controls surrounding an estimate alone does not provide sufficient appropriate audit evidence, auditors also conduct substantive procedures on the reasonableness of accounting estimates the auditors should disregard testing of controls completely, and instead focus on substantive testing the auditors should consider increasing the risk and cost associated with the audit auditors also conduct tests of internal controls pertaining to the reasonableness of accounting estimates