F3FLUID: A formal framework for developing safety‐critical interactive systems in FLUID

Abstract

This paper proposes a unified formal framework, Formal Framework For FLUID (F3FLUID), for the development of safety-critical interactive systems. This framework is based on the Formal Language of User Interface Design (FLUID) pivot modeling language defined in the FORMEDICIS project, which enables high-level system requirements for interactive systems to be specified in the FLUID language. This modeling language is specifically designed for handling concepts of safety-critical interactive systems, including domain knowledge. A FLUID model is used as a source model for the generation of several target models in different modeling languages to support the formal verification methods, such as theorem proving and model checking. In this paper, we use the Event-B modeling language for checking functional behaviors, user interactions, safety properties, and domain properties. A FLUID model is transformed into an Event-B model, and then, the Rodin tool is used to check the internal consistency with respect to the given safety properties. We illustrate the operational semantics of the FLUID language, and the transformation strategy of FLUID models into Event-B models, including the tool development. We use the ProB model checker to analyze the temporal properties and to animate the formalized specification. In addition, an interactive cooperative objects (ICOs) model is derived from the Event-B model for animation, visualization and validation of dynamic behaviors, visual properties, and task analysis. Finally, an industrial case study, complying with the ARINC 661 standard, Multi-Purpose Interactive Applications (MPIA), is used to illustrate the effectiveness of our F3FLUID framework for the development of safety-critical interactive systems.