Despite the increasing maturity of model-driven development (MDD), some research challenges remain open in the field of information systems (IS). For instance, there is a need to improve modelling techniques so that they cover several development stages and they facilitate the transition from analysis to design. This paper presents Message Structures, a technique for the specification of communicative interactions between the IS and its environment. This technique can be used both in analysis and in design. During , it allows abstracting from the technology that will support the IS, and to complement business process modelling with the specification of communicational needs. During design, Message Structures serves two purposes: (i) it allows to systematically derive a model of the IS memory (e.g. a UML class diagram), (ii) and it allows to reason the user interface design using patterns. The technique is part of Communication Analysis, a communication-oriented requirements engineering...