Identifikasi kesalahan utama desain struktur baja pada proyek EPC (Engineering Procurement & Construction) studi kasus pembangunan pabrik pupuk ammonia - urea kujang 1B Cikampek - Jawa Barat = Identification main missdesign of steel structure at EPC project (Engineering procurement & Construction) case study : In construction of ammonia - urea project kujang 1B, Cikampek - Jawa Barat