Semi-Formalization of Requirements for Analogue/Mixed-Signal Products with Application in Automotive Domain

Abstract

The number and complexity of electrical and electronic (E/E) components and systems in a car has increased tremendously in the last years, as a response to the market and users’ demand for quality, automation and safety. Challenges, like management of large number of requirements that define these E/E systems, the connection between requirements in natural language and their implementation and the complexity of the Analogue Mixed-Signal (AMS) domain, can be tackled by more robust requirements through added formality. Semi-formal representation is a reasonable trade-off for adding formality to the requirements without losing the simplicity of the representation of the natural language description. Using semi-formal modelling improves the quality of the requirements and of the development process by identifying the issues in the natural description at an earlier phase. In this book chapter, we describe the modelling of requirements in SysML for an AMS system - a protected power switch, part of an Anti-lock Braking System (ABS). We show that the semi-formalization of the requirements for AMS devices is possible and emphasize its utility in real scenarios. We use SysML in order to represent the requirements from a flat description to a hierarchical organization, to specify the interaction of the components with the environment or with other components, and to describe the structure and the behaviour of the component with the desired amount of detail. The emphasis is put on illustrating the safety mechanisms, required in the implementation and design of the system by safety regulations, such as ISO26262.