Abstract(#br)Making and documenting architectural design decisions becomes increasingly important in the process of software architecting. However, the remoteness of different decision stakeholders, ranging from local distribution in an office environment to globally distributed teams, as well as the different domain knowledge, expertise and responsibilities of the stakeholders hinder effective and efficient collaboration. Existing tools and methods for collaborative architectural decision making focus mainly on sharing and reusing of knowledge, making trade-offs, and achieving consensus, but do not consider the various stakeholders’ decision making constraints due to their roles in the development process. To address this problem, we propose a meta-model for a set of decision making... constraints, with precisely defined semantics, as well as a collaborative architectural decision making approach based on this meta-model. We also present tool support, called CoCoADvISE, which automatically enforces the constraints at runtime. The evaluation of this tool in a controlled experiment with 48 participants shows that our approach, besides preventing constraint violations, significantly increases both the time and effort related efficiency, as well as the effectiveness of users in collaborative decision making.