Relating Decisions in Enterprise Architecture Using Decision Design Graphs

Enterprise Architecture (EA) modeling languages, such as ArchiMate, describe an enterprise holistically. In doing so, they show an enterprise´s business products and services, and how these are realized by IT infrastructure and applications. However, EA modeling languages lack the capability to capture design rationales for decisions that lead to specific architectural designs. In our previous work we presented the EA Anamnesis approach for capturing decision details behind EA models. In doing so, we focused on capturing individual architectural decisions (in terms of alternatives, decision criteria, et cetera). In this paper we present an approach for relating architectural decisions. Using decision design graphs, we make explicit how decisions from different enterprise domains (Business, Application, Technology) relate to each other. For example, how decisions taken on a business level affect IT decisions and vice versa. Our approach is inspired by well-known mechanisms for capturing architectural rationales in software architecture. Specifically we contribute: (1) a decision relationship metamodel for enterprise architecture, with a focus on recording the impact of decisions (2) the notion of a Decision Design Graph for enterprise architecture, a visual representation of this metamodel, and (3) an illustrative example illustrating the potential usefulness of capturing decision relationships.