Why is V&V cumulative coverage report disagree with model coverage highlighting?

I am working in MATLAB R2011b. In some cases after running the Simulink Verification and Validation tool with cumulative condition, decision, and MCDC coverage, the coverage report indicates 100% cumulative coverage while the model coverage highlighting indicates something less than 100% cumulative coverage. Is the model coverage highlighting also recording the cumulative coverage, or is it just showing the current simulation results? Or is this a bug? The coverage tool was run on this same model in MATLAB R2006b, and the results report and model coverage highlighting agreed that the coverage was 100%. Did something change in the tool between MATLAB R2006b and MATLAB 2011b that made the model coverage highlighting tool less reliable?

Answer 1

[Nishaat Vasi]

Model coverage highlighting results depend on the coverage settings you have selected (Tools > Coverage Settings > Report tab). If you selected "Cumulative runs" both the HTML report and model highlighting should display cumulative coverage results.

If the HTML and highlighting results do not match up, it could be a bug. In that case please file a bug report.

[Jeffrey]

I do believe it is a bug. Co-workers that have relied on V&V cumulative coverage analysis in past versions claim that the reports and model diagram highlighting always agreed with each other. In this version, MATLAB 2011b, I am finding that they do not agree, and I have selected the setting that you described above. So that leads me to believe that either MATLAB modified the model highlighting results to no longer illustrate cumulative coverage and only show the last run, or there is indeed a bug.

[Sean de Wolski]

contact support!