Advanced Risk Assessment – Likelihood Estimation and Layers of Protection
Mark Fessler
Risk Assessment Is commonly referred to as a standard practice in our semiconductor and high-tech industries, yet well written guidance on practical application for it still eludes most if not all of us. The “severity of harm” estimation is fairly straight forward, and usually does not bring large disagreements during the design reviews. The estimation of the “likelihood of harm” term, however, is a point of contention almost all the time. There are various books, articles and presentations on how to properly perform a risk assessment, but trying to standardize an approach across a global organization like ASM has been very difficult. This presentation will dive into our company’s new approach to provide our Product Safety Engineering and EHS teams with more consistent “rules’ for estimation based on common equipment hazards we have – regardless of the individual process equipment involved. There is a special focus on how to take credit for expected layers of protection within the likelihood estimation term, and a strong focus on what the minimum design features should be based on the hazard type. ASM hope to “kick-start” this important risk assessment conversation again and looks for industry feedback on our suggested approach with hopes that an industry guideline support document can be written and approved (Related Information to SEMI S10).