Safety Element out of Context - A Practical Approach 2012-01-0033

ISO 26262 is the actual standard for Functional Safety of automotive E/E (Electric/Electronic) systems. One of the challenges in the application of the standard is the distribution of safety related activities among the participants in the supply chain.

In this paper, the concept of a Safety Element out of Context (SEooC) development will be analyzed showing its current problematic aspects and difficulties in implementing such an approach in a concrete typical automotive development flow with different participants (e.g. from OEM, tier 1 to semiconductor supplier) in the supply chain. The discussed aspects focus on the functional safety requirements of generic hardware and software development across the supply chain where the final integration of the developed element is not known at design time and therefore an assumption based mechanism shall be used. The inherent ambiguity deriving from such assumption based distribution of requirements also makes the responsibility allocation on the development chain difficult.

This paper also proposes improvements and extensions of the SEooC concept which may lead to an increased usability of the approach in modern development lifecycles. In order to demonstrate and evaluate the proposed modifications of the SEooC approach, a concrete example (the implementation of a generic AUTOSAR complex device driver for electric motor control) will be described in the paper. The chosen case study is generic and representative for a large spectrum of functional safety relevant automotive applications like Electric Power Steering, Dynamic Steering, X-by-Wire, etc.