What is the difference between “musste”, “muss” and “müsste”?

Question

What are the differences between the following sentences:

Wir wussten nicht, dass die vorhandene Rechtestruktur auch abgebildet werden musste.

Wir wussten nicht, dass die vorhandene Rechtestruktur auch abgebildet werden muss.

Wir wussten nicht, dass die vorhandene Rechtestruktur auch abgebildet werden müsste.

Answer 1

• musste: Past tense. You were required to do it. This can imply that the deadline is already over.
• muss: Present tense. You are required to do it. This can imply that you still have to do it, and that the project is probably not finished.
• müsste: Conjunctive. This might make sense when you're not already into the project, but rather just gave the customer an estimate which does not contain this thing. It can also mean that you still think it should not be done.

The difference between the first two is subtle, and I'm not sure if it will always get the point across. If what you mean is clear from the context, it won't make a huge difference.

Answer 2

Hmmm, to me, it sounds as though only the second one is correct:

The speaker is apparently talking about a task that includes the "Abbildung" of "vorhandene Rechtestruktur". He and his team were not aware of this and didn't include the latter. The fact that he uses "muss" here implies that the task always includes the "AofvR" :)

Another possible sentence would have been:

Wir wussten nicht, dass die vorhandene Rechtestruktur auch hätte abgebildet werden müssen.

This restricts his statement to the particular instance where his team failed to include that thing - i.e. it was required in this particular instance (it may still be a standard requirement, but not necessarily)

Imo this is the correct version of your example no 1 (which I can picture in a casual conversation)

No 3 doesn't really make sense, as far as I can see.