A framework for dependability specification

There are many problems which arise during the development cycle of a complex real time system. Among these are incomplete and inconsistent system level requirements for dependable system operation, incomplete specification for system level fault tolerance, and incomplete plans for test and evaluation. A framework for the specification of dependability properties of a system is an important part of the solution to these problems. Such a framework can be used to guide system engineers through the specification process so that the result is as complete as possible at every stage of the development cycle. It will also provide a means for checking the consistency of specifications and will provide more useful inputs for system evaluation than usual. Finally, such a framework will provide the means for providing additional information for traceability of requirements, design decisions, and test plans. The purpose of the paper is to provide such a framework