Classification by stage, by specialty, by carrier, by time and by responsible person. China Railway Engineering Group Co., Ltd. (hereinafter referred to as "China Railway") adopts the methods of stage classification, specialty classification, carrier classification, time classification and responsible person classification in the project file classification scheme of China Railway Group. The group was established in March 1950, and its headquarters is in Beijing. It integrates infrastructure construction, survey, design and consulting services, engineering equipment and parts manufacturing, real estate development, railway and highway investment and operation.