Contact Us SAEL Company Certification Services Products Training Resources Store Site Safety Index (SSI) As a result of several field failure studies done by exida over many years, evidence is clear that failure rates for the same product vary from site to site. The ratio ranged from 2X to 4X based on product type. The differences seem to be related to site training, site procedures and other variables that some have called “Safety Culture.” exida defines this variable in a four level model called the “Site Safety Index (SSI).” Level Description SSI 4 Perfect - Repairs are always correctly performed. Testing is always done correctly and on schedule, equipment is always replaced before end of useful life, equipment is always selected according to the specified environmental limits and process compatible materials, electrical power supplies are clean of transients and isolated, pneumatic supplies and hydraulic fluids are always kept clean, etc. This level is generally considered to be extremely hard to achieve, but possible in some organizations. SSI 3 Almost Perfect - Repairs are correctly performed. Testing is done correctly and on schedule, equipment is normally selected based on the specified environmental limits and a good analysis of the process chemistry and compatible materials. Electrical power supplies are normally clean of transients and isolated, pneumatic supplies and hydraulic fluids are mostly kept clean, etc. Equipment is replaced before end of useful life, etc. SSI 2 Good - repairs are usually correctly performed. Testing is done correctly and mostly on schedule, most equipment is replaced before end of useful life, etc. SSI 1 Medium - Many repairs are correctly performed. Testing is done and mostly on schedule, some equipment is replaced before end of useful life, etc. SSI 0 None - Repairs are not always done. Testing is not done, equipment is not replaced until failure, etc. SSI is a quantitative model that allows the impact from what many people call “systematic failures” to be realistically included in SIL verification. SSI can provide a way to show the cost impact of alternative operational and maintenance processes. SSI can be comprehensively evaluated with an on-site third party audit. Those interested in this service, please contact exida. A simple question list can also be used to provide an approximate evaluation. Take the Evaluation COMPANY About Us Brochures News Our Team Job Openings PRODUCTS & SERVICES exSILentia Integrated Safety Lifecycle Tool OEMx Reference Materials Online Training Product Certification Functional Safety for the Process Industries Functional Safety for Automotive Functional Safety for Robot / Machine IACS Cybersecurity Alarm Management RESOURCES Blog Videos Webinars White Papers & eBooks Case Studies Newsletter Find Your Local exida Office Copyright © exida 2021 Privacy Policy Terms and Conditions ✖ We use cookies to enhance your experience. By continuing to visit this site you agree to our use of cookies. More info