Part of the teSt phaSe of Software development where, aS new moduleS are integrated into the SyStem and the added functionality iS teSted, previouSly teSted functionality iS re-teSted to aSSure that no new module haS corrupted the SyStem. [Bennatan, E.M., "Software Project Management", 2nd edition, McGraw-Hill International, 1992]. (1995-12-04)