Nyob rau hauv qhov tseeb daim ntawv thov ntawm pub ua machinery, kev sib koom tes ntawm ntau lawm ua hauj lwm mas suav nrog configuration, continuity thiab smoothness. Cov txheej txheem ntawm cov khoom noj khoom haus feem ntau suav nrog tag nrho cov cuab yeej siv tshuab ntsig txog kev tsim khoom noj, txawm tias suav nrog kev thauj mus los, ziab, khaws cia, sau, ua thiab tsim khoom thiab lwm yam khoom siv kho tshuab.
Thawj qhov uas yuav tsum nkag siab txog cov khoom noj khoom haus yog tias nws yuav tsum tau teeb tsa kom loj thiab siab. Nws yog ib qho nyuaj rau ua kom tiav qhov kev cia siab tso zis yog tias tsis muaj lub zog txaus los ua kom tiav qhov kev cia siab tso tawm. Kev teeb tsa tsim nyog thiab lub zog txaus yuav tsum tau ua kom ntseeg tau. Txhawm rau kom ntseeg tau qhov smoothness ntawm cov khoom noj khoom haus, qhov no xav kom peb xaiv cov khoom thaum yuav cov khoom siv thiab cov khoom siv. Tau kawg, kev sib koom ua ke ntawm cov khoom siv ua khoom noj kuj tseem cuam tshuam rau ntau lwm yam, uas yuav tsum tau them sai sai rau hauv kev tsim khoom tiag tiag.
