An IS auditor uses source code comparison software during the evaluation of program change controls primarily to:

Using source code comparison software allows an auditor to evaluate program change controls more effectively by facilitating the examination of source program changes independently. This approach minimizes reliance on information provided by IS personnel, thereby enhancing the objectivity of the audit process. When the auditor can analyze the source code directly, they are better positioned to identify any discrepancies, unauthorized changes, or adherence to established change management protocols.

Additionally, this method can reveal issues that might not be disclosed through standard reporting from IS personnel, such as undocumented changes or errors during the coding process. As a result, the auditor can more confidently assess the integrity and security of the program without bias or influence from those who managed the changes, fostering a thorough and transparent evaluation of the change management controls in place.