In this paper, we consider the European Rail Traffic Management System (ERTMS) as a System-of-Systems (SoS) and propose modeling it using colored Petri nets. We formally control the European rail transport, while guaranteeing a set of cross-border security properties. This becomes an essential and challenging task since each of them have mainly developed safety and trackside rules regardless of its neighbors. The feature of this work lies in the approach that considers ERTMS Level 2 as an SoS and addresses the cross-border railway as a mode management problem. In addition, the aspects of mode activation/deactivation, starting state and handling of resource states common to multiple operating modes are taken into account in the proposed model.

ENASE 2019, 14th International Conference on Evaluation of Novel Approaches to Software Engineering, Heraklion, GRECE, 04-/05/2019 - 05/05/2019

In the context of Safety Critical Systems (SCSs), safety measures derived from the dysfunctional analysis are generally expressed in an informal way. However, in an early phase of SCSs design, there is a need to link these safety measures to Goal-Oriented Requirements Engineering (GORE) concepts. Moreover, the current practice of the safety measures development is not based on a specific goal-oriented control model. Since there are different knowledge domains, there is a lack of a common vocabulary aiming to avoid the semantic heterogeneity between them. Consequently, a common model for an unambiguous knowledge sharing and a full semantic interoperability assurance is missing. In this paper, we propose the Goal-Oriented Safety Management Ontology (GOSMO), a domain ontology, which is grounded in the Unified Foundational Ontology (UFO) and provides a conceptualization and a real-world semantic interpretation of the knowledge matching for SCSs. Furthermore, the proposed safety measures development process is performed using a reinterpretation from the safety point of view of the Organization-Based Control Access (Or-BAC), which was initially developed for the Information Systems (IS) security. The GOSMO aims to capture the alignment between the considered domains concepts through the reference models reuse and the proposed taxonomy based on standards definitions. The proposed ontology is evaluated by the formalization of two cases studies from the railway domain, since it is the target application domain. Finally, the evaluation results show that GOSMO covers and analyses several real critical situations and fulfils its intended purpose.

ICSOFT 2019, 14th International Conference on Software Technologies, Prague, TCHÈQUE, RÉPUBLIQUE, 26-/07/2019 - 28/07/2019

ICSOFT 2018, 13th International Conference on Software Technologies, Porto, PORTUGAL, 26-/07/2018 - 28/07/2018

This paper presents an original experimental protocol, which aims to study human reliability in railway systems by computing the human error probability (HEP) of human operators. The experiment is conducted on a railway traffic management system that places operators in simulated situations involving railway failures. The obtained experimental result is analyzed first by two classical human reliability analysis methods to estimate the HEP of each subject. Then, a model of human operators using valuation-based system is proposed. Finally, a methodology automatically populates the proposed model by allowing the verification of temporal properties on the simulation trace.