I've recently been working with a customer to integrate Wind River Coverage Analysis (formerly known as CoverageScope) with Telelogic Rhapsody within their development tools framework for a mission-critical system.
At first glance, it might seem strange to integrate a code coverage testing tool with a UML design tool, as these aren't even adjacent phases in the software development life cycle (implementation being between them). However, the advent of Eclipse in recent years has helped to break down the silos which used to confine tools individual development life cycle stages and improved development work flow.
The integration enables an application to autocode-generated from Rhapsody and built with Coverage Analysis instrumentation and downloaded and run on the target processor, with coverage results being continuously streamed back to the host and displayed in the Coverage Analysis GUI. This provides immediate feedback of of the level of coverage, and the coverage trend against time (useful for confirming if the test suite tests more and more code over time, or whether it is testing the same code over and over again).
The aspect of the integration which left the biggest impression on me though, was how it enabled the customer to confirm that the right code is executed in response to an event being injected at the UML model level. This is an important aspect of system testing, and it is often difficult to demonstrate the traceability from design to implementation. This was achieved by building the application with both Rhapsody animation and Coverage Analysis instrumentation, and then run or animated on VxWorks with events being injected from Rhapsody and the executed code was shown in Coverage Analysis.
If you're interested in seeing this for yourself, the integration steps are now documented in AppNote-344 on Wind River Online Support website (login required).