Auditors develop overall audit plans to ensure that they obtain "sufficient appropriate audit evidence. To this end, auditors employ various types of audit tests, or audit procedures. The extent to which auditors use different audit procedures and the timing of those procedures is a matter of professional judgment, which depends upon a number of factors. Decisions about the mix of audit procedures and the timing of procedures significantly impact the speed with which an audit report can be issued. What factors will an auditor likely consider when determining the types and timing of audit procedures?