Executable UML

“Today some evidence arises that UML will more and more be used not as a but as a high level programming language. This has some advantages, as if the concepts of UML are executable, they can immediately be animated and tested, or the generated code even be used as implementation. Thus UML probably will have an implementation-oriented semantics describing this animation.”

“In my opinion this sounds great in theory, but unfortunately there are several problems to making this work in practice:”

“Executable UML is at the next higher layer of abstraction, abstracting away both specific programming languages and decisions about the organization of the software so that a specification built in Executable UML can be deployed in various software environments without change.”

“Executable UML is designed to produce a comprehensive and comprehensible model of a solution without making decisions about the organization of the software implementation. It is a highly abstract thinking tool to aid in the formalization of knowledge, a way of thinking about and describing the concepts that make up an abstract solution to a client problem.”

“Executable UML (xUML) consists of UML class diagrams, UML state machines and an action language which complies with the UML action semantics. There are several action languages in use; we refer to for a—somewhat limited—overview. The xUML models to be translated are expressed in the Cassandra/xUML dialect, as developed by KnowGravity.”

“We present a fully automated approach to verifying safety properties of Executable UML models (xUML). Our tool chain consists of a model transformation program which translates xUML models to the process algebra mCRL2, followed by symbolic model checking using LTSmin. If a safety violation is found, an error trace is visualised as a UML sequence diagram. As a novel feature, our approach allows safety properties to be specified as UML state machines.”