A definition for information system survivability

Society has become dependent on information systems. As networks develop into large-scale systems, often critical to personal and business operations, survivability of these systems is imperative. While these systems continue to emerge and grow, answers to questions like: "What does survivability mean?", "How is survivability being measured?", and "How is survivability computed?" become very important. This paper summarizes the standard or lack of standard methods for defining and computing survivability while providing an easy to reference baseline of the current state. It also provides a template for defining survivability to facilitate subsequent research into computational quality attributes by using standard definitions. Where there are gaps or inconsistencies in current research and practice, assessments can be made to continue research and development in the areas most needed to develop taxonomy of survivability.