If you haven't already, I think the first step would be to clearly state what your definition of 'evacuation failure' is. I'm not sure I understand your description:
most common mistakes in evacuation plan and progress.
IN other words, i would like to find records of usual sources of evacuation fails or mistakes. "
No/few evacuations are perfect and all have some failings.
I think looking at some of the well known evacuation disasters (i.e. the most well documented) for specific failings would be the good place to start. Indeed these are often well known either because of the magnitude of the disaster or the extent to which a 'failure' in one form or another has occurred.