Standard 3 (S3) of the ISACA standards states that; 

A) The IS auditor should be professionally competent, having the skills and knowledge to conduct the audit assignment. 

B) The IS auditor should develop and document a risk based audit approach. 

C) The IS auditor should adhere to the ISACA code of professional ethics in conducting audit assignments. 

D) The IS audit function should be independent of the area or activity being reviewed to permit objective completion of the audit