Large industrial facilities are made of numerous systems and sub-systems. Such systems contribute to the overall reliability of the entire unit. The reliability of the entire system is assessed through the process of probability safety analysis. The course will provide an overview of system reliability analysis with a focus on the qualitative and quantitative methods. The principal methods presented in the course include fault tree analysis and event tree analysis. Fault tree diagrams are used to model the possible combinations of equipment failures, human errors, and external conditions that can lead to a specific type of accident, while event trees are used to identify the possible consequence of events or accidents that lead to a particular consequence. Root Cause Failure Analysis is a very effective tool for improving the reliability of facilities, its sub systems and operation. It is a logical, structured, and deductive technique that can identify the causes behind the failure. The course will show how to identify root cause failure and analyze it in practical industrial applications.