Technical Article

Consequently, new approaches are needed to enable functional safety as an integral component in the development of E/E systems. It is important to consider all levels of system designs (Figure 1) and assure that safety goals of the systems are verifiably implemented according to the standard. A key requirement of all current safety standards in automotive and non-automotive industries (e.g. IEC 61511 for the process industry, IEC61513 for nuclear power plants, EN 50128 for railway systems) is that it must be verified that the developed system concept fulfils system safety goals. Safety goals are typically identified in hazard and risk analyses on the functional system level. The functional and technical safety requirements derived from the safety goals are then allocated to system components. Correct implementation of these safety requirements must be assured by a suitable combination of reviews, analyses and tests. The attainment of system safety goals depends on many different factors. One example: faulty programming of software functions or random hardware failures in critical components. As recommended in ISO 26262, such isolated failures can be avoided relatively easily, or can at least be detected and overcome by current development methods. It becomes more problematic when safety goals are affected by a combination of different system factors on different architecture levels. However, in the case of complex systems, such interdependencies can hardly be revealed by conventional, document-based design methods. Here are two The introduction of the international standard ISO 26262 for Functional Safety of Electrical/Electronic Systems in the Automobile has significantly increased awareness of this topic in the industry. As a result, many OEMs and suppliers are seeking approaches that pragmatically fulfill requirements of the standard, while addressing the rising complexity of safety-related functions appropriately. It takes greater work effort to develop safety-critical systems compared to conventional systems. Although constraints remain the same, additional activities related to schedules, resources and costs are unavoidable. Existing development, analysis and test methods and their associated tools are often fragmented and can only be integrated in a uniform process with great effort.