System Safety Engineering & Hazard Analysis: An Introduction by Steve Mattern
Reported by Matthew Coombs, Mechanical Engineering, Occupational Safety and Health
Steve Mattern gave an interesting introduction to system safety engineering and hazard analysis, from the perspective of someone with decades of real life experience, going beyond industry regulations.
Mr Mattern’s presentation began with noting the vast array of definitions of risk, which vary by field. In order to clarify the process of system safety, Mr Mattern recommended using a consolidated set of safety-related vocabulary to define failure pathways. The motives of a system safety engineer to practice system safety Mr Mattern argued is a matter of perspective, targeted on the end goal of minimizing risk to the operator. Placing yourself in the nearest proximity to risk prioritizes system failures.
Explaining his system safety approach, Mr Mattern illustrated with two models. First, the historical model, of “fly-fix-fly” where airplanes were flown until failure, resulting in fleet redesign and retrofitting, until failure occurred again with the process repeating itself. Today’s system safety model is centered around the idea of “first time safe (but not necessarily risk free)” which is defined by identifying the mishap/hazard, determining system-level effects, categorizing hazards, performing in-depth causal analysis, mitigating or controlling hazards to acceptable levels of risk, monitoring the design to ensure implementation of safety requirements, verifying the adequacy of safety requirement implementation, and lastly performing residual risk assessments. Even still however, Mr Mattern noted that acceptable risk is still a subjective decision comparing the acceptability of a mishap to credible alternatives and potential benefits.
In summary, a system safety activity is planned, not an ad hoc activity. The system safety process must be defined with specific tasks, and its implementation produces engineering artifacts to prove you understand the safety risk of the system, and have mitigated that risk to a defined level of acceptance.
Left Photo: Audience consisted for students and faculty from all ERC Programs.
Right Photo: Discussions after the seminar; from the left: Dr. Tom Huston, Mr. Steve Mattern, Mr Matthew Coombs (OSHE PhD student) and Dr. Jay Kim).