The auditor's review of the internal audit and internal control should be conducted in stages, i.e., starting with those areas where his observations can be of most use to the company.
Necessary adjustments can be made on an interim basis until the systems themselves and their degree of reliability facilitate the checks necessary for a complete audit.
Specific work programs should be prepared with the procedures to be applied for each of the areas to be evaluated in order to obtain valid and sufficient evidence and achieve compliance with the audit objectives, and therefore the main elements are planning, execution, preparation of the report and follow-up.
In the planning of an internal audit work, the areas in the company to be audited must be selected and priorities must be established in their execution. This phase allows to identify what must be done during the execution phase and the preparation of the audit report and who and when the tasks must be executed.
It is a dynamic process that, although initiated at the beginning of the audit work, can be modified or continued as the tasks progress. It begins with obtaining the necessary information to define the strategy to be used during the execution and culminates with the detailed definition of the tasks to be performed at that stage.