This paper presents and evaluates the Boundary Diagram Tool for change impact analysis of large Simulink designs of embedded systems. In our previous work, we developed the Reach/Coreach Tool for model slicing within a single Simulink model. The current work extends the Reach/Coreach Tool to trace the impact of model changes through multiple models comprising an embedded system, including network interfaces. The change impact analysis results are represented using various diagrams motivated by industrial needs. Several techniques are used to improve understanding of impact analyses of large industrial systems. The tool has been integrated into the software development process of a large automotive OEM (Original Equipment Manufacturer) to support the following activities: change request analysis and evaluation, implementation, verification and integration. The tool also aids impact analyses required for compliance with functional safety standards. The tool’s effectiveness has been demonstrated on production-scale models.

Abstract: This paper presents a set of tools that provide automatic support for application of some of the traditional soft-ware engineering practices when developing with Simulink. The tools are the: Signature Tool, Reach/Coreach Tool, Data Store Push-Down Tool, and Auto Layout Tool. The Signature Tool extracts the interface of a Simulink subsystem, identifying the subsystem’s explicit, and implicit data flow mechanisms, empowering developers to use the implicit mechanisms more effectively. The Reach/Coreach Tool identifies data and control flow dependencies in a Simulink model and uses the information for model slicing. The view of de-pendencies offered by the tool significantly eases the comprehension of large models. The dependencies can also serve as indicators of alternative designs, and facilitate more effective testing and verification. The Data Store Push-Down Tool restricts the scope of Simulink’s data stores thereby providing improved encapsulation, and increasing modularity. Finally, the Auto Layout Tool significantly decreases the manual effort develop-ers spend in achieving proper layout of models during design and refactoring, and can be used by automated refactoring and transformation tools. 1