In every day life, we encounter events which have very diverse causes, mechanisms of development and consequences. It is the concept of the events′ description that is often of importance in safety or risk studies. In pure technical terms, these events are related to the occurrence of failures, be it of equipment, a device, a system or an item. This paper considers the complex, sometimes problematic, area of the term "failure" and its related characteristics. A two fold objective is pursued in this paper to understand the complexity of this fundamental term. The primary objective is to provide an understanding of the key concepts and classifications. In fact this is related to the functions of an object and its description, classification of failures, the main characteristics of failure, possible causes of failure, failure mechanisms and the consequences of failures. Each of these issues can be subdivided and illustrations are used to differentiate between these subdivisions. For example, to distinguish failure occurrence, the meaning of design failures, manufacturing failures and ageing failure etc is explained. 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, this paper aims to offer an appraisal in understanding failures and their implications.
Received on October 31, 2008, revised on June 9, 2009