2020/05/08 by Jens Kosiol, Daniel Strüber, Kosiol, Jens +5
Computer Science · #Model-Driven Software Engineering Techniques #Semantic Web and Ontologies #Advanced Software Engineering Methodologies
paper · pdf · doi:10.48550/arxiv.2005.04162
Where graphs are used for modelling and specifying systems, consistency is an\nimportant concern. To be a valid model of a system, the graph structure must\nsatisfy a number of constraints. To date, consistency has primarily been viewed\nas a binary property: a graph either is or is not consistent with respect to a\nset of graph constraints. This has enabled the definition of notions such as\nconstraint-preserving and constraint-guaranteeing graph transformations. Many\npractical applications - for example model repair or evolutionary search -\nimplicitly assume a more graduated notion of consistency, but without an\nexplicit formalisation only limited analysis of these applications is possible.\nIn this paper, we introduce an explicit notion of consistency as a graduated\nproperty, depending on the number of constraint violations in a graph. We\npresent two new characterisations of transformations (and transformation rules)\nenabling reasoning about the gradual introduction of consistency: while\nconsistency-sustaining transformations do not decrease the consistency level,\nconsistency-improving transformations strictly reduce the number of constraint\nviolations. We show how these new definitions refine the existing concepts of\nconstraint-preserving and constraint-guaranteeing transformations. To support a\nstatic analysis based on our characterisations, we present criteria for\ndeciding which form of consistency ensuring transformations is induced by the\napplication of a transformation rule. We illustrate our contributions in the\ncontext of an example from search-based model engineering.\n