Supporting Component-based Reuse in CARE

The increased reliance on software in critical applications suggests a greater need for formal methods to be used in the development of such software. A number of formal languages and toolsets exist for developing formally specified and verified software; however experience tells us that the development of formally verified software, even with the current tool support, is an expensive process. By adopting a component-based development methodology, whereby software is developed from reusable components, significant savings can be made. In particular the amount of proof -arguably the most expensive and difficult part of formal development - can be greatly reduced by proving the correctness of reusable components once, off-line, prior to their use. Tools are required which support the user in adapting and retrieving components from libraries of formally specified components. This paper describes extensions to the CARE toolset that support adaptation and retrieval of reusable components