Isivamvo soxinzelelo lweoyile yinxalenye ebalulekileyo ye-injini, esetyenziselwa ukulinganisa uxinzelelo kunye nolawulo, Isetyenziswa ngokubanzi kwimibhobho yenjini eyahlukeneyo yezithuthi kunye neenqanawa, iiprojekthi zokusetyenzwa kwamanzi, uhlolo kunye nolawulo lweenkqubo zerial yeshishini, iprojekthi yolawulo lwe-hydraulic kunye ne-pneumatic s, njl.