The ACE Framework has a language to model argumentation graphs, were the
arguments, conflicts, preferences and inferences between arguments of distinct stakeholders can be explicitly represented. Moreover, ACE algorithms formally identify impasses or consensus. This paper presents a well conceived way of dealing with viewpoints by explicitly representing them and allowing for the identification of those arguments that have no conflicts, that is which can be said to be accepted by the different stakeholders involved.
The abstract says:
“A requirements engineering artifact is valid relative to the stakeholders of the system-to-be if they agree on the content of that artifact. Checking relative validity involves a discussion between the stakeholders and the requirements engineer. This paper proposes (I) a language for the representation of information exchanged in a discussion about the relative validity of an artifact; (ii) the acceptability condition, which, when it verifies in a discussion captured in the proposed language, signals that the relative validity holds for the discussed artifact and for the participants in the discussion; and (iii) reasoning procedures to automatically check the acceptability condition in a discussions captured by the proposed language.”
More details, see the paper: Analysis of Multi-Party Agreement in Requirements Validation