Initially, in the event of a technical system failure, the questions of safety and costs take center stage. However, it is only through the systematic analysis of the damage-causing mechanisms that one obtains the key to sustainable prevention. The defective component serves as the data carrier for the material and its condition, as well as for the stresses it has experienced and the mechanism of its failure. The examination methods of materials science and materials engineering are capable of deciphering this information. A comparison of the actual state versus the desired state allows for the identification of the damage trigger. This book has emerged from a seminar of the same name. Over more than 30 years, this seminar has demonstrated that damage cases predominantly result from violations of known technical rules. Therefore, this reference work focuses on that aspect.