For example, if you are doing a process audit and part of the process includes taking SPC (Statistical Process Control) data, you can audit whether or not the operator/technician is taking the data. But - you cannot determine whether the operator understands SPC and what s/he is doing unless your knowledge of SPC is sufficient.
One of the typical expectations in internal auditor courses, much like lead auditor courses, is the expectation that you understand ISO 9001 (and/or QS-9000 (now IATF 16949) ) and can interpret it with respect to your company. But - more about this later.
The bottom line is if you don t know about what you re auditing the effectiveness of your audit will be limited.
Caution II
This guide is not intended to address specific interpretation(s) of ISO 9001, QS-9000 (now IATF 16949) or any other specific standard or customer requirement. It is *assumed* that anyone auditing will have the appropriate background / experience / education in that which s/he is auditing.
It is *assumed* that we all know you cannot audit anything you do or are responsible for. Conflict of Interest is the phrase.
ISO 19011 - Quality and Environmental Management Systems Auditing Forum Discussions