The University of Southampton
University of Southampton Institutional Repository

Formal verification and validation of run-to-completion style state charts using Event-B

Formal verification and validation of run-to-completion style state charts using Event-B
Formal verification and validation of run-to-completion style state charts using Event-B

State chart notations with ‘run to completion’ semantics are popular with engineers for designing controllers that react to environment events with a sequence of state transitions but lack formal refinement and rigorous verification methods. State chart models are typically used to design complex control systems that respond to environmental triggers with a sequential process. The model is usually constructed at a concrete level and verified and validated using animation techniques relying on human judgement. Event-B, on the other hand, is based on refinement from an initial abstraction and is designed to make formal verification by automatic theorem provers feasible. Abstraction and formal verification provide greater assurance that critical (e.g. safety or security) properties are not violated by the control system. In this paper, we introduce a notion of refinement into a ‘run to completion’ state chart modelling notation and leverage Event-B’s tool support for theorem proving. We describe the difficulties in translating ‘run to completion’ semantics into Event-B refinements and suggest a solution. We illustrate our approach and show how models can be validated at different refinement levels using our scenario checker animation tools. We show how critical invariant properties can be verified by proof despite the reactive nature of the system and how behavioural aspects of the system can be verified by testing the expected reactions using a temporal logic, model checking approach. To verify liveness, we outline a proof that the run to completion is deadlock-free and converges to complete the run.

Event-B, Refinement, Run to completion, State charts
1614-5046
Morris, K.
840d0e33-3782-45b8-921f-e644f3255059
Snook, C.
b2055316-9f7a-4b31-8aa1-be0710046af2
Hoang, T. S.
dcc0431d-2847-4e1d-9a85-54e4d6bab43f
Hulette, G.
fea06d59-b391-40e2-b72d-b8f219baa59d
Armstrong, R.
c1cf75df-a0d8-4416-a8b8-3b75736ff8aa
Butler, M.
54b9c2c7-2574-438e-9a36-6842a3d53ed0
Morris, K.
840d0e33-3782-45b8-921f-e644f3255059
Snook, C.
b2055316-9f7a-4b31-8aa1-be0710046af2
Hoang, T. S.
dcc0431d-2847-4e1d-9a85-54e4d6bab43f
Hulette, G.
fea06d59-b391-40e2-b72d-b8f219baa59d
Armstrong, R.
c1cf75df-a0d8-4416-a8b8-3b75736ff8aa
Butler, M.
54b9c2c7-2574-438e-9a36-6842a3d53ed0

Morris, K., Snook, C., Hoang, T. S., Hulette, G., Armstrong, R. and Butler, M. (2022) Formal verification and validation of run-to-completion style state charts using Event-B. Innovations in Systems and Software Engineering. (doi:10.1007/s11334-021-00416-4).

Record type: Article

Abstract

State chart notations with ‘run to completion’ semantics are popular with engineers for designing controllers that react to environment events with a sequence of state transitions but lack formal refinement and rigorous verification methods. State chart models are typically used to design complex control systems that respond to environmental triggers with a sequential process. The model is usually constructed at a concrete level and verified and validated using animation techniques relying on human judgement. Event-B, on the other hand, is based on refinement from an initial abstraction and is designed to make formal verification by automatic theorem provers feasible. Abstraction and formal verification provide greater assurance that critical (e.g. safety or security) properties are not violated by the control system. In this paper, we introduce a notion of refinement into a ‘run to completion’ state chart modelling notation and leverage Event-B’s tool support for theorem proving. We describe the difficulties in translating ‘run to completion’ semantics into Event-B refinements and suggest a solution. We illustrate our approach and show how models can be validated at different refinement levels using our scenario checker animation tools. We show how critical invariant properties can be verified by proof despite the reactive nature of the system and how behavioural aspects of the system can be verified by testing the expected reactions using a temporal logic, model checking approach. To verify liveness, we outline a proof that the run to completion is deadlock-free and converges to complete the run.

Text
Morris2022_Article_FormalVerificationAndValidatio - Version of Record
Available under License Creative Commons Attribution.
Download (2MB)

More information

Accepted/In Press date: 15 August 2021
e-pub ahead of print date: 4 March 2022
Additional Information: Funding Information: Sandia National Laboratories is a multimission laboratory managed and operated by National Technology & Engineering Solutions of Sandia, LLC, a wholly owned subsidiary of Honeywell International Inc., for the US Department of Energy’s National Nuclear Security Administration under contract DE-NA0003525. Publisher Copyright: © 2022, National Technology & Engineering Solutions of Sandia, LLC. Copyright: Copyright 2022 Elsevier B.V., All rights reserved.
Keywords: Event-B, Refinement, Run to completion, State charts

Identifiers

Local EPrints ID: 457537
URI: http://eprints.soton.ac.uk/id/eprint/457537
ISSN: 1614-5046
PURE UUID: 6fd0cab2-e0ca-4a93-993f-ee958eb5ac34
ORCID for C. Snook: ORCID iD orcid.org/0000-0002-0210-0983
ORCID for T. S. Hoang: ORCID iD orcid.org/0000-0003-4095-0732
ORCID for M. Butler: ORCID iD orcid.org/0000-0003-4642-5373

Catalogue record

Date deposited: 10 Jun 2022 16:41
Last modified: 11 Jun 2022 01:43

Export record

Altmetrics

Contributors

Author: K. Morris
Author: C. Snook ORCID iD
Author: T. S. Hoang ORCID iD
Author: G. Hulette
Author: R. Armstrong
Author: M. Butler ORCID iD

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of http://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×