Engineering safety-related requirements for software-intensive systems

Many software-intensive systems have significant safety ramifications and need to have their associated safety-related requirements properly engineered. It has been observed by multiple consultants, researchers, and authors that inadequate requirements are a major cause of accidents involving software-intensive systems. Yet in practice, there is very little interaction between the requirements and safety disciplines and little collaboration between their respective communities. Most requirements engineers know little about safety engineering, and most safety engineers know little about requirements engineering. Also, safety engineering typically concentrates on architectures and designs rather than requirements because hazard analysis typically depends on the identification of hardware and software components, the failure of which can cause accidents. This leads to safety-related requirements that are often ambiguous, incomplete, and even missing. The tutorial begins with a single common realistic example of a safety critical system that will be used throughout to provide good examples of safety-related requirements. The tutorial then provides an introduction to requirements engineering for safety engineers and an introduction to safety engineering for requirements engineers. The tutorial then provides clear definitions and descriptions of the different kinds of safety-related requirements and finishes with a practical process for producing them.