ance ▁test ings ▁are ▁often ▁performed . ▁This ▁is ▁a ▁grey ▁area ▁as ▁many ▁different ▁opinions ▁exist ▁as ▁to ▁what ▁the ▁stages ▁of ▁testing ▁are ▁and ▁how ▁much , ▁if ▁any ▁iteration ▁occurs . ▁Iter ation ▁is ▁not ▁generally ▁part ▁of ▁the ▁water fall ▁model , ▁but ▁the ▁means ▁to ▁rect ify ▁defect s ▁and ▁validate ▁fixes ▁prior ▁to ▁deployment ▁is ▁incorpor ated ▁into ▁this ▁phase . ▁ ▁The ▁following ▁are ▁types ▁of ▁testing ▁that ▁may ▁be ▁relevant , ▁depending ▁on ▁the ▁type ▁of ▁system ▁under ▁development : ▁▁ ▁De fect ▁testing ▁the ▁failed ▁scenarios , ▁including ▁▁ ▁Path ▁testing ▁ ▁Data ▁set ▁testing ▁ ▁Unit ▁testing ▁ ▁System ▁testing ▁ ▁Integr ation ▁testing ▁ ▁Black - box ▁testing ▁ ▁White - box ▁testing ▁ ▁Reg ression ▁testing ▁ ▁Autom ation ▁testing ▁ ▁User ▁accept ance ▁testing ▁ ▁Software ▁performance ▁testing ▁ ▁Training ▁and ▁transition ▁▁ ▁Once ▁a ▁system ▁has ▁been ▁stabil ized ▁through ▁ade qu ate ▁testing , ▁the ▁SD LC ▁ens ures ▁that ▁proper ▁training ▁on ▁the ▁system ▁is ▁performed ▁or ▁documented ▁before ▁transition ing ▁the ▁system ▁to ▁its ▁support ▁staff ▁and ▁end ▁users . ▁Training ▁usually ▁covers ▁oper ational ▁training ▁for ▁those ▁people ▁who ▁will ▁be ▁responsible ▁for ▁supporting ▁the ▁system ▁as ▁well ▁as ▁training ▁for ▁those ▁end ▁users ▁who ▁will ▁be ▁using ▁the ▁system ▁after ▁its ▁delivery ▁to ▁a ▁production ▁operating ▁environment . ▁ ▁After ▁training ▁has ▁been ▁successfully ▁completed , ▁systems ▁engine ers ▁and ▁developers ▁transition ▁the ▁system ▁to ▁its ▁final ▁production ▁environment , ▁where ▁it ▁is ▁intended