The present disclosure describes methods, systems, and computer program products for measuring strength of a unit test. One computer-implemented method includes receiving software unit source code associated with a unit test, analyzing a line of the software unit source code for removability, initiating, by operation of a computer, modification of the software unit source code to remove the line of the software unit source code and create a modified software unit, initiating execution of the modified software unit using the unit test, determining success or failure of a unit test execution, and analyzing a next line of the software unit source code for removability.