The current technology-driven transformation of business processes (and everyday life) must be embedded in collaborative decision making processes. Simple design representations that require no knowledge of specific modelling languages facilitate the involvement of multiple stakeholders. However, they must be related in a structured and at the same time creative way to be an effective means in developing a shared design understanding. This paper proposes concepts for an integrated use of two design rationale representations: scenarios as concrete descriptions of situations of use and QOC diagrams as more abstract descriptions of whole design spaces. Corresponding tool support is presented which supports the intertwined creation of scenarios and QOC diagrams. The tool can easily be extended to include other design representations as demonstrated at the example of integrating personas and use cases.