▁as ▁a ▁consequence ▁of ▁purs uing ▁value ▁improvements . ▁ ▁Vert ical ▁slice ▁is ▁a ▁type ▁of ▁mil estone , ▁benchmark , ▁or ▁dead line , ▁with ▁emphas is ▁on ▁demonstr ating ▁progress ▁across ▁all ▁components ▁of ▁a ▁project . ▁ ▁Virtual ▁Design ▁and ▁Const ruction ▁( VD C ) ▁is ▁the ▁use ▁of ▁integrated ▁multi - dis cipl inary ▁performance ▁models ▁of ▁design - const ruction ▁projects , ▁including ▁the ▁Product ▁( i . e ., ▁facilities ), ▁Work ▁Process es ▁and ▁Organ ization ▁of ▁the ▁design ▁- ▁construction ▁- ▁operation ▁team ▁in ▁order ▁to ▁support ▁explicit ▁and ▁public ▁business ▁object ives . ▁ ▁W ▁▁▁ ▁W ide band ▁Del phi ▁is ▁a ▁cons ensus - based ▁estimation ▁technique ▁for ▁estim ating ▁effort . ▁ ▁Work ▁in ▁project ▁management ▁is ▁the ▁amount ▁of ▁effort ▁applied ▁to ▁produce ▁a ▁deliver able ▁or ▁to ▁accomplish ▁a ▁task ▁( a ▁terminal ▁element ). ▁ ▁Work ▁Break down ▁Str ucture ▁( W BS ) ▁is ▁a ▁method ▁and ▁a ▁kind ▁of ▁representation ▁that ▁defines ▁a ▁project ▁and ▁groups ▁the ▁project ’ s ▁discrete ▁work ▁elements ▁in ▁a ▁way ▁that ▁helps ▁organ ize ▁and ▁define ▁the ▁total ▁work ▁scope ▁of ▁the ▁project . ▁A ▁Work ▁break down ▁structure ▁element ▁may ▁be ▁a ▁product , ▁data , ▁a ▁service , ▁or ▁any ▁combination . ▁W BS ▁also ▁provides ▁the ▁necessary ▁framework ▁for ▁detailed ▁cost ▁estim ating ▁and ▁control ▁along ▁with ▁providing ▁guidance ▁for ▁schedule ▁development ▁and ▁control . ▁ ▁Work ▁package ▁is ▁a ▁subset ▁of ▁a ▁project ▁that