How long did the regression take before release? If reduced to 20 critical test cases, how much time was spent?

In a typical project, regression testing before release can take from a few hours to several days, depending on the scope of functionality and the number of test cases. For example, a full run of all tests may take 1-2 days.

If the set is reduced to 20 critical test cases, the time is significantly shortened — usually to a few hours (1-3 hours), allowing for faster feedback and quicker releases. This approach is often used for smoke testing or sanity checks after a build.

Example: if a full regression contains 200 tests and takes 8 hours, then 20 critical tests can be performed in about 0.8 hours (48 minutes), considering proportionality and optimization.