A Systematic Approach and Guidelines to Developing a Triple Graph Grammar

Engineering processes are often inherently concurrent, involving multiple stakeholders working in parallel, each with their own tools and artefacts. Ensuring and restoring the consistency of such artefacts is a crucial task, which can be appropriately addressed with a bidirectional transformation (bx ) language. Although there exist numerous bx languages, often with corresponding tool support, it is still a substantial challenge to learn how to actually use such bx languages. Triple Graph Grammars (TGGs) are a fairly established bx language for which multiple and actively developed tools exist. Learning how to master TGGs is, however, currently a frustrating undertaking: a typical paper on TGGs dutifully explains the basic "rules of the game" in a few lines, then goes on to present the latest groundbreaking and advanced results. There do exist tutorials and handbooks for TGG tools but these are mainly focussed on how to use a particular tool (screenshots, tool workflow), often presenting exemplary TGGs but certainly not how to derive them systematically. Based on 20 years of experience working with and, more importantly, explaining how to work with TGGs, we present in this paper a systematic approach and guidelines to developing a TGG from a clear, but unformalised understanding of a bx