ABSTRACT Storage tanks are critical elements within oil facilities not because of their failure rate, but because of their critical function and the high environmental consequences when they fail. The presented analysis allows determining the probability of failure of storage tanks considering the most probable failure scenarios of this equipment. The utilized methodology considers the uncertainties associated with material degradation mechanism such as general corrosion, pitting and cracking induced by corrosion. The analytical formulations of the time dependant degradation of the isolated mechanisms and the system conformed by the conjunction of them are considered. Obtained results allow determining the contribution of the individual scenarios in the system reliability. Additionally, the probability of failure results and the maintenance cost are used to determine the optimum inspection time based on minimum costs criterion
