Andreas Abele

Automatic allocation of safety integrity levels

In this paper, we describe a concept for the automatic allocation of general Safety Integrity Levels (SILs) to subsystems and components of complex hierarchical networked architectures that deliver sets of safety critical functions. The concept is generic and can be adapted to facilitate the safety engineering approach defined in several standards that employ the concept of integrity or assurance levels including ISO 26262, the emerging automotive safety standard. SIL allocation is facilitated by HiP-HOPS, an automated safety analysis tool, and can be performed in the context of development using EAST-ADL2, an automotive architecture description language. The process rationalizes complex risk allocation and leads to optimal/economic allocation of SILs.

Model-based safety engineering of interdependent functions in automotive vehicles using EAST-ADL2

For systems where functions are distributed but share support for computation, communication, environment sensing and actuation, it is essential to understand how such functions can affect each other. Preliminary Hazard Analysis (PHA) is the task through which safety requirements are established. This is usually a document-based process where each system function is analyzed alone, making it difficult to reason about the commonalities of related functional concepts and the distribution of safety mechanisms across a systemof-systems. This paper presents a model-based approach to PHA with the EAST-ADL2 language and in accordance with the ISO/DIS 26262 standard. The language explicitly supports the definition and handling of requirements, functions and technical solutions, and their various relations and constraints as a coherent whole with multiple views. We show in particular the engineering needs for a systematic approach to PHA and the related language features for precise modeling of requirements, user functionalities, system operation contexts, and the derived safety mechanisms.

EPM: a prototype tool for variability management in component hierarchies

EPM is a prototypical research tool that combines traditional component modeling means with a comprehensive variability management support. In addition to ordinary containment hierarchies of components, the tool provides a few selected system modeling and product management capabilities, e.g. separate modeling of the systems software and hardware architecture and an end-customer / marketing-oriented view on the systems variability. In this article we present EPM and briefly describe its main functionality.