▁end - product ▁and ▁therefore ▁helps ▁the ▁designer . ▁ ▁Rel ational ▁data ▁model ▁( if ▁applicable ): ▁A ▁data ▁model ▁is ▁an ▁abstract ▁model ▁that ▁describes ▁how ▁data ▁is ▁represented ▁and ▁used . ▁If ▁an ▁object ▁database ▁is ▁not ▁used , ▁the ▁rel ational ▁data ▁model ▁should ▁usually ▁be ▁created ▁before ▁the ▁design , ▁since ▁the ▁strategy ▁chosen ▁for ▁object - rel ational ▁mapping ▁is ▁an ▁output ▁of ▁the ▁O O ▁design ▁process . ▁However , ▁it ▁is ▁possible ▁to ▁develop ▁the ▁rel ational ▁data ▁model ▁and ▁the ▁object - orient ed ▁design ▁artifact s ▁in ▁parallel , ▁and ▁the ▁growth ▁of ▁an ▁artifact ▁can ▁stim ulate ▁the ▁ref in ement ▁of ▁other ▁artifact s . ▁ ▁Life ▁cycle ▁ ▁Management ▁and ▁control ▁▁ ▁The ▁SD LC ▁phases ▁serve ▁as ▁a ▁program m atic ▁guide ▁to ▁project ▁activity ▁and ▁provide ▁a ▁flexible ▁but ▁consistent ▁way ▁to ▁conduct ▁projects ▁to ▁a ▁depth ▁matching ▁the ▁scope ▁of ▁the ▁project . ▁Each ▁of ▁the ▁SD LC ▁phase ▁object ives ▁are ▁described ▁in ▁this ▁section ▁with ▁key ▁deliver ables , ▁a ▁description ▁of ▁recommended ▁tasks , ▁and ▁a ▁summary ▁of ▁related ▁control ▁object ives ▁for ▁effective ▁management . ▁It ▁is ▁critical ▁for ▁the ▁project ▁manager ▁to ▁establish ▁and ▁monitor ▁control ▁object ives ▁during ▁each ▁SD LC ▁phase ▁while ▁executing ▁projects . ▁Control ▁object ives ▁help ▁to ▁provide ▁a ▁clear ▁statement ▁of ▁the ▁desired ▁result ▁or ▁purpose ▁and ▁should ▁be ▁used ▁throughout ▁the ▁entire ▁SD LC ▁process . ▁Control ▁object ives ▁can ▁be ▁grouped ▁into ▁major ▁categories