Functional safety is the discipline of ensuring that safety-related systems perform their required functions correctly when needed, including responding to hazardous conditions. In industrial plants, these functions may be provided by alarms, interlocks, or safety instrumented systems that help bring a process to a safe state.
It matters in cybersecurity because changes to network access, software, or system availability can affect how safety functions operate. A security measure should therefore be assessed against the plant’s safety design and lifecycle, rather than assumed to be harmless or unsafe. OT teams coordinate safety and security reviews, change management, and risk analysis to check that protections do not undermine critical timing, availability, or safe operation.