The influence of components ageing through the lifetime of the plant plays an important role in safety assessments, representing an important concern for many types of organizations. The book presents an initiative in assessing the ageing effects using the probabilistic safety assessment studies. The book includes chapters presenting general aspects of ageing phenomena, probabilistic safety assessment considerations, and possible applications of the study that incorporates the ageing effects. The evaluation of ageing effects in a specific case study, including the modelling methodology to incorporate the effects of ageing in probabilistic safety assessment study is presented. The case study results are illustrated with graphical representations. The book should help shed some light on area of ageing effects evaluations, and should be especially useful to professionals in reliability, safety and risk assessment field, or anyone else who may be considering evaluating the ageing effects.