Functional safety plays a major role for embedded systems
The complexity of embedded systems is constantly increasing – as are the safety requirements. In this interview, Prof Dr Peter Fromm from Darmstadt University of Applied Sciences explains the increasing importance of functional safety for embedded systems and gives practical advice for safety development.
Safety in the embedded system industry
Prof Fromm, how do you define functional safety?
Prof Fromm: The key point here is certainly the following: if the operation of a system can jeopardise the environment and, in particular, people, higher reliability requirements must be placed on this system.
Can you give an example of this?
Prof Fromm: In my view, we need to consider both safe system functions and protective functions. In the case of safe system functions, traditional – often mechanical – solutions are replaced by electronic systems. One example of this is »X-by-wire« systems. The main aim here is to realise at least as high a level of reliability with the new technology as with the classic approach.
Practical implementation of functional safety
The MISRA rules are used in the automotive sector to avoid errors during programming. What do the MISRA rules achieve and where is there a need to catch up?
Prof Fromm: MISRA is certainly one of the better programming standards and reduces the C/C++ language scope to a safe and well-defined subset – which is also demonstrated by the fact that this standard is used in many areas outside the automotive sector and has now even found its way into the curriculum of technical degree programmes.
Especially when I, as a software developer, use MISRA during development, I can eliminate weaknesses in the code before the review. But even MISRA is not a silver bullet. In particular, design errors in the code and other more complex problems cannot be found with it. The human expert review is therefore still necessary and important. However, the focus of the review can then be placed on the »exciting« problems.
