How can a company establish a baseline measurement of its safety culture against which to gauge improvement? The Site Safety IndexTM (SSI) quantifies in part (on a scale of 0 – 4) the degree to which a company’s end-user practices support the attainment and retention of an appropriate safety culture for operations and maintenance. Further, the SSI can be used to appropriately adjust parameters that directly impact measures of safety such as probability of failure on demand (PFDavg). Thus, the impacts of safety culture can be further quantified and the effects of changes to safety culture can be assessed.