In systems engineering, dependability is a measure of a system's availability, reliability, maintainability, and in some cases, other characteristics such as durability, safety and security. In real-time computing, dependability is the ability to provide services that can be trusted within a time-period. The service guarantees must hold even when the system is subject to attacks or natural failures. The International Electrotechnical Commission (IEC), via its Technical Committee TC 56 develops and maintains international standards that provide systematic methods and tools for dependability assessment and management of equipment, services, and systems throughout their life cycles. The IFIP Working Group 10.4 on "Dependable Computing and Fault Tolerance" plays a role in synthesizing the technical community's progress in the field and organizes two workshops each year to disseminate the results. Dependability can be broken down into three elements: Attributes - a way to assess the dependability of a system Threats - an understanding of the things that can affect the dependability of a system Means - ways to increase a system's dependability Some sources hold that word was coined in the nineteen-teens in Dodge Brothers automobile print advertising. But the word predates that period, with the Oxford English Dictionary finding its first use in 1901. As interest in fault tolerance and system reliability increased in the 1960s and 1970s, dependability came to be a measure of [x] as measures of reliability came to encompass additional measures like safety and integrity. In the early 1980s, Jean-Claude Laprie thus chose dependability as the term to encompass studies of fault tolerance and system reliability without the extension of meaning inherent in reliability. The field of dependability has evolved from these beginnings to be an internationally active field of research fostered by a number of prominent international conferences, notably the International Conference on Dependable Systems and Networks, the International Symposium on Reliable Distributed Systems and the International Symposium on Software Reliability Engineering.