ABSTRACT
Methodological approaches related to availability as well as to safety must be introduced to improve the dependability of an industrial production site within the CIM context. Risk analysis, classicaly used to determine the safety level of the system, has been developed out of reliability methods employed to study the high risk systems in such domains as : space, nuclear and chemical industries. Large difficulties are encountered in adapting these methods to the domain of Operational Safety of automatic production installations. However, methods such as the “Failure Mode Effect and Criticity Analysis” (FMECA) and “Fault tree Analysis” still represent the main tolls available to the risk manager. Those two methods should be used as complementary to each other in order to obtain an adequate appreciation about: temporal considerations, integration of operating modes and quantification. In this paper, we go beyond the traditional reliability methods in order to provide the necessary operational aid insisting particularly on defining critical situations and recovery from them. The originality of the work carried out consists of directly connecting a fault tree to the production site. The management of different critical events should be achieved in real time in order to allow the elaboration of recovery strategies (redundancy, re-initialisation, intervention,…). Furthermore, introducing the generation of scenarii of events during supervision should not adversly affect the operational aid temporal efficiency. Hence the FtA is parallelily implemented using transputers, greatly enhancing processing time.
