Hi,
I understand you concern of initiating such audits in a place where functions are centralized. Because, it is a universal truth that HR audit is best done in an environment of high level of diversification and decentralization. But only considering your status as a trainee and the probable learning you might get from the topic of HR Audit, here are few notes:
For sure HR Audit is one area of tangible impact which implies critical review and assessment of policies, schemes and procedures in human resource management. The primary aim of such audits is to determine whether personnel policies and practices are consistent with the organizational objectives.
While auditing, the auditor depends largely on personnel records and reports supplied by the personnel department. More importantly, employees may consider personnel audits as an unappealing or faultfinding exercise. To avoid such troubles, forward-looking approach is required.
Now:
Would a trainee be allowed access to personnel records of staffs (some of which may be extremely confidential) ?
Is the organization willing to defend problems resulting out of this audit, if any ?
Do you have enough time to convince staffs on the need and worth of (a) such audits and (b) the forward-looking approach to minimize future concerns/ operational issues in HR?
Probably, these may be certain concerns you might have to reconsider.
But of-course, the topic is extremely interesting and is already being considered as one of the key performance indicators (KPIs) of HR Managers / Heads.
Good Luck