>The assertion has been made that typical applications have between 40%-50% of their code actually run during testing.
>
>I am curious to see what percentage of code you test (actually run during development/unit test/system testing) for:
>
>1) The development of a system from scratch.
Each working component initially. I then feed it to superusers in a test area. Next I test at a beta site, then distribute the release.

>2) The development of a new/replacement system but using code parts (including classes, functions, etc.) from existing and well-running systems.
As above

>3) Developing revisions to an existing application.
Usually get a superuser to test it out, then test at a beta site and then propagate the final version

>Thanks for your reply.

Having said that, some errors get reported years after distribution!
I find that users will break the application faster than superusers.