The failure phenomenon: a critique

Throughout every day life there are many events encountered where their causes, mechanisms of development and consequences are very diverse. In undertaking a safety or risk assessment it is the concept of the events´ description that is often of importance. In pure technical applications these events are related to the occurrence of failure, be it of equipment, a device, a system or an item. The theory speaks about failure itself, its mechanisms and circumstances of occurrence, but at the same time appropriate terminology is needed to describe these conditions. For observing, dealing and handling failures a probabilistic or deterministic (logic) approach can be followed. This paper considers the complex, sometimes problematic, area of the term “failure” and its related characteristics. The contribution aims to detail the total complexity of this fundamental term. A two fold objective approach is taken. The primary objective is to address each of these complexity issues providing an understanding of the key concepts and classifications. These are related to the functions of an object and their description, classification of failures, the main characteristics of failure, the possible causes of failure, mechanisms of failure and consequences of failure. Each of these issues can be subdivided and engineering examples are used to illustrate and differentiate between such subdivisions, for example to distinguish for failure occurrence the meaning of design failures, manufacturing failures and ageing failure etc. The secondary objective is related to information sources. To gain information about a failure it may need to be found or transferred from a variety of sources, these sources have been identified and discussed. In conclusion the paper serves to form a complete picture to aid the understanding and implications of failures.