There have been various proposals for the formalization of appropriate viewpoint-based frameworks. The model that we intend to devise attempts to provide a basis for conceptual model integration particularly with the existence of partial ignorance and uncertainty. The model will try to formalize the degree of uncertainty present in experts’ expressions, and proposes tools for conceptual model integration and formal consensus building between the involved viewpoints. Categories and Subject Descriptors D.2.1 [Requirements/ Specifications]: Methodologies General Terms Design, Reliability, Management Keywords Viewpoint Integration, Collaborative Modeling, Conceptualization, Inconsistency Management, Belief Theory