In the modified excel sheet for the admin part you have mentioned (both external - you're using customers to tell you about problems! Any internal monitoring?) could please explain more?
My comment was on the fact that the only way/s you appeared to have of finding out IF things were being done accurately was via your
customers telling you. And while I think that's fine re. customer satisfaction, I'm less convinced that it's a good thing for other objectives. In this case, if it's important (customer messages not getting passed on correctly sounds so to me) I think I'd want to have internal ways of finding that out, not waiting to find out via customers, which could be too late!
But also, possibly various assumptions I'm making are wrong - I'm a little thrown by your use of the term 'monitoring' you see - I'd be more inclined to call it 'how measured/assessed.' (that is why, you see, it's so difficult to give accurate advice on objectives at a remote distance and without knowing any of the relevant factors!)
honestly I cant come up with proper admin objectives since they are not much involved in the company in terms of responsibilities. they either answering calls, prepare employees applications such as leaves, visas... or a point of communication with our Group HR. so i would like to ask for suggestions on some general Admin objectives.
Hmm - my first response is, fine, if they're not involved, then get rid of them and save the money

Are they really irrelevant to quality of service? If they are, fine, don't bother with objectives. You need them only at '
relevant functions and levels' - so if they're not relevant, fine. There's no point in just throwing in objectives for the sake of having them.
But if, for example, they make mistakes on the visas, say, and you don't get someone with permission to work in time to meet a client deadline... wouldn't that affect service quality? You might try something like 'complete all paperwork accurately first time, with no rework/returns'.
PS - All -it's quality
management we should be talking about (or at least I am), not 'QA'. And while many manufacturing organisations may well have a separate 'Quality Dept' or a 'QA Dept', I cannot think of one single service organisation I've consulted to that does (or would want to). Service companies are
different to manufacturing and so are their quality systems! While yes the broad principles apply, their application often differs hugely.