Abstract
In process industries common practice, failure rates (FRs) have an essential role for evaluating accident likelihood, which, in turn, drives most decisions of Competent Authorities, including installation licensing and land use planning (LUP). FRs currently in use for process equipment derive basically a few from major systematic studies conducted in the sixties and seventies. Many new materials, new production and management method have been introduced and their effects on aging mechanisms on a large scale are still unknown. Authorities could make questionable decisions, trusting in poor or generic FRs. A few European Competent Authorities are trying to face the problem, by stating a set of trusted FRs, suitable just for LUP. INAIL, as in charge for pressure equipment control throughout Italy, is gathering data for updating generic failure frequencies. The proposed solution is aiming to provide "numbers", on which Authorities and enterprises can count, but above all to pool the knowledge about failure modes, in order to better address the management of equipment throughout the process industry. A hard work of knowledge organization is necessary but it may dramatically improve probabilistic risk assessment, LUP decisions, as well as risk based maintenance and inspection planning.
