Hi Michael,

Thanks for posting!

Yes, this is certainly possible. You'll need to create a custom engine mode, which needs to have the tests to execute automatically setting overridden, containing a filter by the execution time of the test. You might also want to add an extra condition on the filter so that NCrunch will also execute tests that haven't been executed yet, as otherwise the execution time won't become available.

I would generally recommend using categories if possible. This is because test execution time can be quite variable. If you have a unit test that has a single execution run over 100ms, NCrunch then won't run this unit test again until it's targeted manually and reruns with a lower execution time.