Application of fuzzy sets in evaluation of failure likelihood

Estimation of failure likelihood for technical objects is a very difficult process because the information about the process is often uncertain and imprecise. Assessment of risk related in catastrophic damages is very difficult, particularly in systems where damage causes threat of human life or serious economic losses. Methods like FMEA and FMECA applied to evaluation of risk of designed systems do not give the full information about meaning of results of possible failure. Therefore the risk evaluation method, when risk is a product of failure likelihood and degree of failure, was proposed.