Umshini wokomisa umshini osebenzisa ukushisa ukuze uhwamuke futhi ukhiphe umswakama (ngokuvamile amanzi noma ezinye izingxenye zoketshezi eziguquguqukayo) entweni, ngaleyo ndlela kutholwe into eqinile enomswakama othile. Kuwuhlobo lwemishini eyimishini esetshenziselwa ukufeza inqubo yokomisa yezinto.
Imishini yokomisa yesimanje ekuqaleni yayisebenzisa inqwaba-imishini yokomisa emibhede engaguquki{1}. Ukusetshenziswa kwemishini yokomisa umhubhe maphakathi nekhulu le-19 kwaphawula ukuthuthukiswa kwezomisa kusuka kunqwaba kuya ekusebenzeni okuqhubekayo. Imikhiqizo eminingi yezimboni idinga ukomiswa esigabeni esithile sokukhiqiza, futhi izinto ezisetshenziswayo zidinga umswakama othize ukuze zicutshungulwe, zibunjwe, noma zifakwe imbudumbudu. Izinto zokomisa zingahlukaniswa ngokwezici ezihlukene ezifana nenqubo yokusebenza, ingcindezi yokusebenza, indlela yokushisa, ukunyakaza kwezinto ezimanzi, noma isakhiwo.
