Marcelo; Just tying to find answers here but I reckon the conversation would go like this:
Me to designer - what are you trying to achieve? And why
Desinger: I'm trying to design a house so the people out the back can build it
Me: how do you do that?
Designer: I use xyz software program
Me: how do you know it's the best way to do it?
Designer; I dont but thats the way they want it done
Me: how do you know it's the right thing to do?
Designer: do you mind, I'm busy I gotta get this done today.
Also, would not a good answer also be:
Designer: Because this is how mangement have planned the process and I need to carry out work according the process management designed.
If this happen:
1 - the auditte is not a good auditee
2 - the auditor is not a good auditor
Question and examples are like this - questions and example. You need to focus that, as an auditor, you are looking for audit evidence.
Questions like these might help you try to begin looking for audit evidence, but if you think the question, or answer, is so straight forwarded, I suggest you might rethink your audit strategy and your role as an auditor.