HR Audit

Hi- I was wondering how often other Credit Unions perform an HR audit and is performed by internal audit or is it outsourced? 

If it is performed internally, are you simply looking at controls and procedures? Or do you look into employee file testing (current and terminated), HR reputation including corporate recruitment, benefits & compensation, employee complaints, etc. 

Or do you have it outsourced to perform a full HR assessment looking at all aspects as I mentioned above? 

Thank you for your feedback.