It seemed to nobody that UT ( modular tests) on which many, (majority) actually brake system development, thus, that are not capable to reveal what or the errors which are distinct from elementary and primitive, which and without tests are visible to any for whom is available though an experience drop. The dude here wrote a subsystem, one thousand tests (functions UT). Transited half a year, it was required to change subsystems, to change. 80 % of all tests, naturally, after modification, do not transit, it is necessary to rewrite UT according to new realities, expending time twice more than on modification of the subsystem. In three months it was required to change/add again a functional of the unit-again fuss with alteration of tests etc... So what for they generally then there rested? The functional is checked by the functional tests, difficult errors perfectly come to light manual testing, search of errors and bugs-lines and . UT are represented by result any terribly the reason which has become by a mode. What think about it?