The central audit issue is whether the validation programs in the data editing system
are functioning correctly and have continued to function as intended throughout the
period. Testing the logic of a validation program, however, represents a significant undertaking.
The auditor may decide to rely on the quality of other controls to provide
the assurance needed to reduce substantive testing. For example, after reviewing systems
development and maintenance controls, the auditor may determine that controls over
original program design and testing and subsequent changes to programs are effective.
This evidence permits the auditor to assess the risk of material program errors at a low
level and thus reduce the substantive tests related to the audit objective of accuracy