Safety ADD: A Tool for Safety-Contract Based Design

Safety ADD is a tool for working with safety contracts for software components. Safety contracts tie safety related properties, in the form of guarantees and assumptions, to a component. A guarantee is a property the component promises to hold, on the premise that the environment provides its associated assumptions. When multiple software components are integrated in a system, Safety ADD is used to verify that the guarantees and assumptions match when there are safety-related dependencies between the components. The initial goal of Safety ADD is to investigate how safety contracts can be managed and used efficiently within the software design process. It is implemented as an Eclipse plug in. The tool has two main functions. It gives designers of software components a way to specify safety contracts, which are stored in an XML format and shall be distributed together with the component. It also gives developers who integrate multiple software components in their systems a tool to verify that the safety contracts are fulfilled. A graphical editor is used to connect guarantees and assumptions for dependent components, and an algorithm traverses all such connections to make sure they match.