When must you stop testing?

It is very difficult to determine as many modern software applications are complex and run in such an interdependent environment that complete testing is never possible.

Though, common factors that help in deciding when to stop are:

- Deadlines to release or test is over.

- Test cases are finished with certain percentage passed

-Test budget is over

- Coverage of code/requirements/functionality has reached a specified point

- Bug rate is below a certain level

- Alpha or beta testing period has ended