(ii) Test data
Test data consists of data submitted by the auditor for processing by the client’s computer system. The principle objective is to test the operation of application controls. For this reason, the auditor will arrange for dummy data to be processed that includes many error conditions, to ensure that the client’s application controls can identify particular problems.
Examples of errors that might be included:
supplier account codes that do not exist
employees earning in excess of a certain limit
sales invoices that contain addition errors
submitting data with incorrect batch control totals.
Data without errors will also be included to ensure ‘correct’ transactions are processed properly.
Test data can be used ‘live’, ie during the client’s normal production run. The obvious disadvantage with this choice is the danger of corrupting the client’s master files. To avoid this, an integrated test facility will be used (see other techniques below). The alternative (dead test data) is to perform a special run outside normal processing, using copies of the client’s master files. In this case, the danger of corrupting the client’s files is avoided – but there is less assurance that the normal production programs have been used.