An extensible formal semantics for UML activity diagrams

TL;DR

This paper develops an operational formal semantics for UML activity diagrams to improve model verification, transformation validation, and standard compliance assessment, addressing the language's extensibility and under-specification issues.

Contribution

It introduces an extensible structural operational semantics for UML activity diagrams, enabling formal verification and validation of models and extensions.

Findings

Semantics implemented and tested successfully.

Supports model correctness verification.

Facilitates validation of language extensions.

Abstract

This paper presents an operational semantics for UML activity diagrams. The purpose of this semantics is three-fold: to give a robust basis for verifying model correctness; to help validate model transformations; and to provide a well-formed basis for assessing whether a proposed extension/interpretation of the modeling language is consistent with the standard. The challenges of a general formal framework for UML models include the semi-formality of the semantics specification, the extensibility of the language, and (sometimes deliberate, sometimes accidental) under-specification of model behavior in the standard. Our approach is based on structural operational semantics, which can be extended according to domain-specific needs. The presented semantics has been implemented and tested.