3 Definitions Common Cause Failure (CCF) – Loss of function to multiple structures, systems, or components due to a shared root cause IEEE 603-2018]. Concurrent Trigger – A triggering condition on multiple segments/elements that occur at or about the same time. Defensive Measures – Design attributes to prevent, limit, or reduce the likelihood of a software CCF. Design Attributes – Hardware and software design features that contribute to high dependability. Such features include builtin fault detection and failure management schemes, internal redundancy and diagnostics, and use of software and hardware architectures designed to minimize failure consequences and facilitate problem diagnosis Adopted from RIS 2002-22 Supplement 1, Section 3.1.1].
