Abstract
Safety assurance cases (ACs) are structured arguments that assert the safety of cyber-physical systems. ACs use reasoning steps, or strategies, to show how a safety claim is decomposed into subclaims which are then supported by evidence. In practice, ACs are informal, and thus it is difficult to check whether these decompositions are valid and no subclaims are missed. This may lead to the approval of fallacious safety arguments and thus the deployment of unsafe systems. Fully formalizing ACs to facilitate rigorous evaluation is not realistic due to the complexity of creating and comprehending such ACs. We take an intermediate approach by formalizing several types of decomposition strategies, proving the conditions under which they are deductive, and applying them as templates that guard against common errors in ACs. We demonstrate our approach on two scenarios: creation of ACs with deductive reasoning steps and evaluation and improvement of existing ACs.
This is a preview of subscription content, log in via an institution to check access.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
References
Basir, N., Denney, E., Fischer, B.: Deriving safety cases from automatically constructed proofs. In: Proceedings of International Conference on Systems Safety (2009)
Basir, N., Denney, E., Fischer, B.: Deriving safety cases for hierarchical structure in model-based development. In: Schoitsch, E. (ed.) SAFECOMP 2010. LNCS, vol. 6351, pp. 68–81. Springer, Heidelberg (2010). https://doi.org/10.1007/978-3-642-15651-9_6
Bloomfield, R., Bishop, P., Jones, C., Froome, P.: ASCAD: Adelard Safety Case Development Manual, London, UK (1998). Accessed 28 Jan 2020
Brunel, J., Cazin, J.: Formal verification of a safety argumentation and application to a complex UAV system. In: Proceedings of SafeComp 2012, pp. 307–318 (2012)
Chechik, M., Salay, R., Viger, T., Kokaly, S., Rahimi, M.: Software assurance in an uncertain world. In: Hähnle, R., van der Aalst, W. (eds.) FASE 2019. LNCS, vol. 11424, pp. 3–21. Springer, Cham (2019). https://doi.org/10.1007/978-3-030-16722-6_1
Cruanes, S., Hamon, G., Owre, S., Shankar, N.: Tool integration with the evidential tool bus. In: Giacobazzi, R., Berdine, J., Mastroeni, I. (eds.) VMCAI 2013. LNCS, vol. 7737, pp. 275–294. Springer, Heidelberg (2013). https://doi.org/10.1007/978-3-642-35873-9_18
Denney, E., Naylor, D., Pai, G.: Querying safety cases. In: Bondavalli, A., Di Giandomenico, F. (eds.) SAFECOMP 2014. LNCS, vol. 8666, pp. 294–309. Springer, Cham (2014). https://doi.org/10.1007/978-3-319-10506-2_20
Denney, E., Pai, G.: A lightweight methodology for safety case assembly. In: Ortmeier, F., Daniel, P. (eds.) SAFECOMP 2012. LNCS, vol. 7612, pp. 1–12. Springer, Heidelberg (2012). https://doi.org/10.1007/978-3-642-33678-2_1
Denney, E., Pai, G.: A formal basis for safety case patterns. In: Bitsch, F., Guiochet, J., Kaâniche, M. (eds.) SAFECOMP 2013. LNCS, vol. 8153, pp. 21–32. Springer, Heidelberg (2013). https://doi.org/10.1007/978-3-642-40793-2_3
Denney, E., Pai, G.: Towards a formal basis for modular safety cases. In: Koornneef, F., van Gulijk, C. (eds.) SAFECOMP 2015. LNCS, vol. 9337, pp. 328–343. Springer, Cham (2015). https://doi.org/10.1007/978-3-319-24255-2_24
Denney, E., Pai, G.: Tool support for assurance case development. J. Automated Soft. Eng. 25(3), 435–499 (2018)
Denney, E., Pai, G., Whiteside, I.: Formal foundations for hierarchical safety cases. In: Proceedings of HASE 2015, pp. 52–59. IEEE (2015)
Fung, N.L.S., Kokaly, S., Di Sandro, A., Salay, R., Chechik, M.: MMINT-A: a tool for automated change impact assessment on assurance cases. In: Gallina, B., Skavhaug, A., Schoitsch, E., Bitsch, F. (eds.) SAFECOMP 2018. LNCS, vol. 11094, pp. 60–70. Springer, Cham (2018). https://doi.org/10.1007/978-3-319-99229-7_7
Graydon, P.J.: Formal assurance arguments: a solution in search of a problem? In: Proceedings of ICDSN 2015, pp. 517–528. IEEE (2015)
Greenwell, W.S., Knight, J.C., Holloway, C.M., Pease, J.J.: A taxonomy of fallacies in system safety arguments. In: Proceedings of ISSC 2006 (2006)
GSN Working Group: GSN Community Standard Version 2, York, UK (2011). http://www.goalstructuringnotation.info/. Accessed 28 Jan 2020
Haddon-Cave, C.: The Nimrod Review: An Independent Review into the Broader Issues Surrounding the Loss of the RAF Nimrod MR2 Aircraft XV230 (2009)
ISO: ISO 26262: Road Vehicles - Functional Safety, International Organization for Standardization (ISO) (2011)
Keller, R.M.: Formal verification of parallel programs. Commun. ACM 19(7), 371–384 (1976)
Kokaly, S.: Managing Assurance Cases in Model Based Software Systems. Ph.D. thesis, McMaster University (2019)
Matsuno, Y.: D-Case Editor: A Typed Assurance Case Editor. University of Tokyo (2011)
Matsuno, Y.: A design and implementation of an assurance case language. In: Proceedings of ICDSN 2014, pp. 630–641. IEEE (2014)
Matsuno, Y., Taguchi, K.: Parameterised argument structure for GSN patterns. In: Proceedings of ICQS 2011, pp. 96–101. IEEE (2011)
NASA: AdvoCATE Tool Webpage (2019). https://ti.arc.nasa.gov/tech/rse/research/advocate/. Accessed 28 Jan 2020
Nemouchi, Y., Foster, S., Gleirscher, M., Kelly, T.: Isabelle/SACM: computer-assisted assurance cases with integrated formal methods. In: Ahrendt, W., Tapia Tarifa, S.L. (eds.) IFM 2019. LNCS, vol. 11918, pp. 379–398. Springer, Cham (2019). https://doi.org/10.1007/978-3-030-34968-4_21
Nipkow, T., Paulson, L.C., Wenzel, M.: Isabelle/HOL: A Proof Assistant for Higher-Order Logic, LNCS, vol. 2283. Springer, Heidelberg (2002). https://doi.org/10.1007/3-540-45949-9
Norell, U., Danielsson, N.A., Abel, A.: Agda Wiki Page (2020). https://wiki.portal.chalmers.se/agda/pmwiki.php. Accessed 28 Feb 2020
Object Management Group (OMG): Structured Assurance Case Metamodel (SACM). http://www.omg.org/spec/SACM/. Accessed 22 Feb 2020
Rushby, J.: Formalism in safety cases. In: Dale, C., Anderson, T. (eds.) Proceedings of SSS 2010, pp. 3–17. Springer, London (2010). https://doi.org/10.1007/978-1-84996-086-1_1
Rushby, J.: Logic and epistemology in safety cases. In: Bitsch, F., Guiochet, J., Kaâniche, M. (eds.) SAFECOMP 2013. LNCS, vol. 8153, pp. 1–7. Springer, Heidelberg (2013). https://doi.org/10.1007/978-3-642-40793-2_1
Takeyama, M.: “D-Case in Agda” Verification Tool (D-Case/Agda). https://wiki.portal.chalmers.se/agda/pmwiki.php?n=D-Case-Agda.D-Case-Agda. Accessed 25 Feb 2020
Yamamoto, S.: Argument algebra: a formalization of assurance case development. In: Kravets, A., Shcherbakov, M., Kultsova, M., Iijima, T. (eds.) JCKBSE 2014. CCIS, vol. 466, pp. 717–725. Springer, Cham (2014). https://doi.org/10.1007/978-3-319-11854-3_62
Yamamoto, S., Matsuno, Y.: An evaluation of argument patterns to reduce pitfalls of applying assurance case. In: 2013 1st International Workshop on Assurance Cases for Software-Intensive Systems (ASSURE), pp. 12–17. IEEE (2013)
Author information
Authors and Affiliations
Corresponding author
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2020 Springer Nature Switzerland AG
About this paper
Cite this paper
Viger, T., Salay, R., Selim, G., Chechik, M. (2020). Just Enough Formality in Assurance Argument Structures. In: Casimiro, A., Ortmeier, F., Bitsch, F., Ferreira, P. (eds) Computer Safety, Reliability, and Security. SAFECOMP 2020. Lecture Notes in Computer Science(), vol 12234. Springer, Cham. https://doi.org/10.1007/978-3-030-54549-9_3
Download citation
DOI: https://doi.org/10.1007/978-3-030-54549-9_3
Published:
Publisher Name: Springer, Cham
Print ISBN: 978-3-030-54548-2
Online ISBN: 978-3-030-54549-9
eBook Packages: Computer ScienceComputer Science (R0)