You are the auditor of Hi Tech Innovations (HTI). HTI has an internal audit department that perform operational audits, such as the testing for internal controls over inventory, cost allocation etc.

a) Explain the Canadian Auditing Standards (CAS 610) requirements that the external auditors must follow to "evaluate the internal audit function" before any reliance can be placed on the internal audit department.

b) Discus two similarities and two differences between internal and external auditors.