ra ul ic ▁components ; ▁ ▁Road ▁characteristics . ▁ ▁Us es ▁ ▁In ▁many ▁cases , ▁the ▁most ▁effective ▁way ▁to ▁develop ▁an ▁embedded ▁system ▁is ▁to ▁connect ▁the ▁embedded ▁system ▁to ▁the ▁real ▁plant . ▁In ▁other ▁cases , ▁H IL ▁simulation ▁is ▁more ▁efficient . ▁The ▁metric ▁of ▁development ▁and ▁test ▁efficiency ▁is ▁typically ▁a ▁formula ▁that ▁includes ▁the ▁following ▁factors : ▁ 1 . ▁Cost ▁ 2 . ▁D uration ▁ 3 . ▁Saf ety ▁ 4 . ▁Fe as ibility ▁ ▁The ▁cost ▁of ▁the ▁approach ▁should ▁be ▁a ▁measure ▁of ▁the ▁cost ▁of ▁all ▁tools ▁and ▁effort . ▁The ▁duration ▁of ▁development ▁and ▁testing ▁affect s ▁the ▁time - to - market ▁for ▁a ▁planned ▁product . ▁Saf ety ▁factor ▁and ▁development ▁duration ▁are ▁typically ▁equ ated ▁to ▁a ▁cost ▁measure . ▁Specific ▁conditions ▁that ▁war rant ▁the ▁use ▁of ▁H IL ▁simulation ▁include ▁the ▁following : ▁ ▁En han cing ▁the ▁quality ▁of ▁testing ▁ ▁T ight ▁development ▁sched ules ▁ ▁High - bur den - rate ▁plant ▁ ▁Early ▁process ▁human ▁factor ▁development ▁ ▁En han cing ▁the ▁quality ▁of ▁testing ▁ ▁Us age ▁of ▁H IL s ▁enh ances ▁the ▁quality ▁of ▁the ▁testing ▁by ▁increasing ▁the ▁scope ▁of ▁the ▁testing . ▁ ▁Ide ally , ▁an ▁embedded ▁system ▁would ▁be ▁tested ▁against ▁the ▁real ▁plant , ▁but ▁most ▁of ▁the ▁time ▁the ▁real ▁plant ▁itself ▁impos es ▁limitations ▁in ▁terms ▁of ▁the ▁scope ▁of ▁the ▁testing . ▁For ▁example , ▁testing ▁an ▁engine