In the audit planning stage, audit evidence is the information that the auditor considers when determining the most effective and efficient approach for the audit. For example, reliability of internal control procedures, and analytical review systems. In the control testing stage, audit evidence is used by the auditor to consider the mix of audit test of controls and audit substantive tests.
In both phases—planning and control testing—the auditor uses audit evidence to make decisions about the most efficient and effective methods for auditing. This involves evaluating internal controls and analytical review systems in planning, and deciding on test procedures in control testing.