Formal validation of viewpoint specifications

How can we be sure that a set of viewpoints is valid, in the sense that it is possible to build a system consistent with each and every one of them? Our approach is based on the idea of amalgamating the individual viewpoints into a single coherent whole. A formal study of this process leads to a proposed approach for combining viewpoints that identifies conditions under which the resulting specification reflects all the properties of the constituent viewpoints. These ideas are applied to the development of Z specifications, and it is shown how they might be used in other contexts.