Luc Engelen

Extracting Models from ISO 26262 for Reusable Safety Assurance

As more and more complex software is deployed in safety-critical embedded systems, the challenge of assessing the safety of those systems according to the relevant standards is becoming greater. Due to the extensive manual work required, validating compliance of these systems with safety standards is an expensive and time-consuming activity; furthermore, as products evolve, re-assessment may become necessary. Therefore, obtaining reusable assurance data for safety assessment or re-assessment is very desirable. In this paper, we propose a model-based approach for assuring compliance with safety standards to facilitate reuse in the assessment, qualification and certification processes, using the automotive safety standard ISO 26262 as a specific example. Three different modeling techniques are described: A structure model is introduced to describe the overall structure of the standard; a rule-based technique is used for extracting the conceptual model from it; and a mapping to the software and systems process engineering metamodel provides a description of its processes. Finally, validation in the context of a concrete use case in the FP7 project OPENCOSS shows that the resulting models of our approach resemble the industrial models, but that they, inevitably, require the fine-tuning of domain experts.

The third rewrite engines competition

This paper presents the main results and conclusions of the Third Rewrite Engines Competition (REC III). This edition of the competition took place as part of the 8th Workshop on Rewriting Logic and its Applications (WRLA 2010), and the systems ASF+SDF, Maude, Stratego/XT, Tom, and TXL participated in it.

A Modeling Approach to Support Safety Assurance in the Automotive Domain

As safety standards are widely used in safety-critical domains, such as ISO 26262 in the automotive domain, the use of safety cases to demonstrate product safety is stimulated. It is crucial to ensure that a safety case is both correct and clear. To support this, we proposed to make use of modeling techniques to support safety assurance in the automotive domain. Continuing on our previous work, a rule-based approach enables us to extract a conceptual model from safety standards or project guidelines. Then, by applying structured English using an SBVR vocabulary, the safety case is linked to the conceptual model, and the content of it is enforced to be well structured and controlled. The contribution of the explicit link between the safety case and the conceptual model is to reduce the ambiguity of natural language, and to increase the confidence in the claimed safety assurance. Finally, tooling is developed that enables syntax highlighting and content assistance while editing safety cases.

VPDSL: A DSL for Software in the Loop Simulations Covering Material Flow

We present an approach to model hardware configurations of complex manufacturing systems such as ASMLs lithography machines. These hardware configurations consist of actuator and sensor elements which are controlled by system software that consists of over 35 million lines of code. To minimize the cost of testing and system integration, software simulators of hardware configurations are used-acting as virtual hardware platforms on which the real control software can be executed and tested. An important aspect in such simulation and testing is material flow (specifically wafer flow) in the machine. To support the effective and efficient realization of simulators covering material flow, we defined a domain specific language (DSL) for modelling the hardware configurations to be simulated, and used a model-driven engineering approach to generate the software components implementing the simulators. The DSL can be used to specify not only nominal (i.e. good weather) behaviour but also simulation based fault injection scenarios. The overall approach reduces the cost of early hardware-software integration and enables simulating scenarios that cannot be executed on real machines because they are difficult or hazardous to carry out.

From Conceptual Models to Safety Assurance

Safety assurance or certification is one of the most costly and time-consuming tasks in automotive, railway, avionics, and other safety-critical domains. Different transport sectors have developed their own specific sets of safety standards, which creates a big challenge to reuse pre-certified components and share expertise between different transport sectors. In this paper, we propose to use conceptual models in the form of metamodels to support certification data reuse and facilitate safety compliance. A metamodel transformation approach is outlined to derive domain or project specific metamodels using a generic metamodel as basis. Furthermore, we present a metamodel refinement language, which is a domain-specific language that facilitates simple refinement of metamodels. Finally, we use two case studies from the automotive domain to demonstrate our approach and its ability to reuse metamodels across companies.