Tsis yog-qhov nruab nrab yog hais txog qhov tsis paub tseeb, tsis yog series, lossis cov qauv txheej txheem tsis zoo. Cov khoom tsis zoo hauv kev lag luam hauv kev lag luam feem ntau yog xa mus rau tej yam khoom xws li hlua, hlua, steel silos, rooj vag, nkhaus, thiab npog. Vim hais tias tsis yog-txheem qhov nruab nrab ntawm cov khoom siv, seb qhov tsim ntawm cov qauv tsis yog tus qauv tsim nyog los yog tsis muaj ib qho tseem ceeb hauv kev tsim kho thiab kev tsim khoom. Yog hais tias tus qauv tsim tsis zoo, nws yuav ua rau pov tseg hauv kev ua thiab yuav ua teeb meem hauv kev teeb tsa. Ua teeb meem rau kev tsim khoom.
Tib neeg tab tom nrhiav kev tsim cov khoom ntiag tug, thiab hnub no txoj kev ua los ntawm txoj kev ua tau hloov maj mam hloov ntawm cov khoom siv yav dhau los rau cov khoom me me. Vim li no, muaj ntau qhov chaw tshwj xeeb uas siv los ntawm cov tuam txhab uas muaj cov nqi ntau heev ntawm kev pab los yog hu ua non-standard parts. Yuav kom ua tau raws li qhov yuav tsum tau muaj kev tshawb nrhiav ntawm cov khoom tsis yog hauv cov kab hauv cov kab ua haujlwm, qhov kev paub ntaus tsis zoo no tau tsim. Kev soj ntsuam ntawm on-line ntawm ib lossis ob hom ntawm cov qauv tsis-txheem tau pom tau los ntawm kev siv cov khoom noj tsis zoo, kev teeb tsa qhov chaw nyob thiab cov chaw nruab nrab, thiab cov kev ntsuas qhov muag tsis pom kev. Kev ntsuam xyuas ntawm cov qauv tsis-tus qauv pab txoj kev tshuaj xyuas qhov tseeb thiab qhov ua tau zoo.