Risk assessment of machinery system with respect to safety and cyber security

There is a long tradition at machinery sector to make risk assessments considering safety issues. Currently, the assessment is made usually according to ISO 12100 and if the focus is on control systems then often according to ISO 13849-1. Cyber security issues have emerged to publicity mainly because of the threat associated to money and confidentiality. It is evident that security may affect also safety. Therefore, machine builders have increased their interest in security issues also. Current paper is related to cases where cyber security issues may have an effect on machinery safety. There are already several standard proposals related to the connection between cyber security and safety, but the field is still evolving. The idea is that security issues must not impair safety, but on the other hand, the required resources must be in line with the risk. The paper addressed the needs to combine risk assessments to cover both safety and related cyber security issues. The security issues covered in this case are then limited to safety functions of control systems, communication, safety of machinery misuse (interfaces) and other safety-related situations that are found rare but possible.