Probabilistic studies deal mainly with the production availability of production systems (RAM studies – Reliability, Availability, Maintainability) and the probability of good functioning of safety systems (SIL studies -Safety Integrity Level). Performed during the various development phases of the projects they aim to estimate the impact of the chosen architectures, of the equipment failures and the operation and maintenance policies on production (oil, gas, flaring) or safety. They allow to identify the weak points, to verify that the targets are reached and they provide clues for improvement.This course mainly describes the approach developed by TOTAL for RAM studies and briefly shows how it can also be used for SIL studies. The structure is the following :

1- RAM / HIPS studies within the safety and dependability framework and challenges.
2- Notions about Monte Carlo simulation.
3- Introduction to stochastic Petri nets.
4- RAM Examples.
5- HIPS Examples.
6- Software demonstrations.
7- Conclusions