ABSTRACT
In the 1980s, the emergence of cheap computers facilitated the management of large amounts of data and boosted the development of incident databases. During the last twenty years, mandatory incident reporting systems, Flight Data Recorder read-out programs, and penalty free confidential reporting systems have flourished within airlines and within national and international bodies (ICAO, IATA, CAAs, and Accident Investigation Authorities). A safety occurrence analysis includes one or more references to "safety principles". The limitations of traditional "normative" approaches to safety mainly stem from the fact they oversimplify causality. Because of obvious limitations in manpower and financial resources, not all incidents can be processed the same way. Some of them will be merely encoded in a few words into a local data base, if not simply ignored. A comprehensive probability assessment would consider the probability of recurrence of a given incident and the probabilities of all the possible outcomes of all the possible accident scenarios associated with that incident.
