Dependability

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.^[1] In real-time computing, dependability is the ability to provide services that can be trusted within a time-period.^[2] 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^[3] 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