Mgbe ụfọdụ, a ọrụ Ọdịdị nwere ike ghara na-agụnye ọrụ, ma na-adabere naanị na onwe ha contractors. Industries, ebe a ọrụ na-emekarị na-agụnye ụgbọ ala ahịa, onwunwe ahịa, mkpuchi ntinye akwụkwọ, na ọtụtụ ahịa ọrụ. Na United States, a ezigbo ala na ụlọ ore na ihe ịga nke ọma na-ere a onwunwe nwere ike na-anakọta a ọrụ nke 6% nke ire ere. Ajụjụ: Gịnị ọrụ na-ahụkarị na?
ire ụgbọala, ire ụlọ, akwụkwọ mkpuchi, na ọtụtụ ọrụ ahịa