Research On Automatic FTA And FMEA Techniques For Process Analysis And Improvement

Fault Tree Analysis (FTA) and Failure Mode and Effect Analysis (FMEA), two of the most widely used safety analysis techniques, can be combined together to analyze and evaluate safety problems in a process in an attempt to reduce the occurrence of severe hazards or their consequences. This paper focuses on applying these two techniques to process analysis, and finding out defects or weaknesses in processes, and finally leading to improved processes with higher safety. FMEA and FTA techniques are usually manually performed by skilled experts, which may be time-consuming, error-prone, and tedious when applied to complex processes. How to automatically perform FTA and FMEA techniques to analyze processes is the main objective of this paper. We also do research on finding an effective way to combine these two complementary techniques to analyze processes. The details of the above problems discussed in this paper are as follows,1. Framework of automatic safety analysis techniques for process analysis and improvement. We propose a framework that adopts several static analysis techniques to analysis weaknesses in processes after modeling them in Little-JIL language.2. Approach and tool support of an automatic FMEA technique. We propose an approach that automatically derives effect trees from Little-JIL processes.3. Approach and tool support of an automatic FTA technique. We propose an approach that automatically generates fault trees from Little-JIL processes, as well as computes MCSs of each fault tree.4. Optimization methods of addressing scaling and looping issues. To address the scaling issue, two optimizations are applied before the fault tree is derived, Step Abstract and Step Removal. Another optimization, Single-Cause Event Elimination, is applied after the fault tree is derived. To solve the looping issue, we propose an algorithm that can detect and remove all loops in the fault tree in a simple way.5. Approach of combining FTA and FMEA techniques. Both the failure mode and the effect in our automatic FMEA approach can be used as top-events in our automatic FTA approach to automatically generate fault trees for them, which realizes the combination of FMEA and FTA techniques. That is to say, given a failure mode, both effects (bottom-up) and causes (top-down) can be generated for it, and results can be combined to improve processes.Through applying the proposed framework and automatic techniques in analyzing two real-world medical processes which are adopted by Bayestate medical center in USA, it is proved that our approach can be used to systematically detect safety issues in processes. Subsequent improvement measures will be made to processes, which may lead to improved safety. Our research has directive significance for future work on safety analysis and improvement of processes both theoretically and in practice.