John Colley

Co-simulation environment for Rodin: landing gear case study

This work in progress presents a prototype multi-simulation environment for the Rodin platform that enables import, co-modelling and co-simulation of dynamic models and formal Event-B specifications, which can help in the design of mixed discrete-event/continuous-time systems. The proposed solution is based on the Functional Mock-up Interface standard and ProB animator for Event-B. The involved technologies and co-simulation semantics are explained, followed by a demonstration of preliminary results, obtained from a landing gear case study.

A Systematic Approach to Requirements Driven Test Generation for Safety Critical Systems

We describe ongoing work into the generation of test cases for safety critical systems using Event-B and the Rodin toolset. Verification of software to DO-178C is a two stage process. First a suite of test cases must be validated against the system requirements (requirements coverage), and then the software implementation is verified using the validated test suite. During verification of the implementation structural coverage is also measured.

Modelling and Refinement in CODA

This paper provides an overview of the CODA framework for modelling and refinement of component-based embedded systems. CODA is an extension of Event-B and UML-B and is supported by a plug-in for the Rodin toolset. CODA augments Event-B with constructs for component-based modelling including components, communications ports, port connectors, timed communications and timing triggers. Component behaviour is specified through a combination of UML-B state machines and Event-B. CODA communications and timing are given an Event-B semantics through translation rules. Refinement is based on Event-B refinement and allows layered construction of CODA models in a consistent way.

A practical approach for closed systems formal verification using event-b

Assurance of high integrity systems based on closed systems is a challenge that becomes difficult to overcome when a classical testing approach is used; in particular the evidence generated from a classical testing approach may not meet the objectives of rigorous standards. This paper presents a new approach for the formal verification of closed systems, in particular commercial off the shelf (COTS) products. The approach brings together the formal language Event-B, mathematical proof theory and the Rodin toolset and provides the mechanism for creating abstract models of closed systems and to then verify these system properties against operational requirements. From an industrial perspective this approach represents a step change in the use and successful integration of closed systems; using formal methods to guarantee their integration and functionality. The outcome of the proof of concept will provide a solution that will increase the level of confidence on complex system of system solutions containing closed systems. Moreover, it will support the production of safety-cases by providing formal proofs of a systems correctness.