Invited Review A review of planning and scheduling systems and methods for integrated steel production Lixin Tang a , Jiyin Liu b, * , Aiying Rong b , Zihou Yang a a DepartmentofSystemsEngineering,NortheasternUniversity,Shenyang,People'sRepublicofChina b DepartmentofIndustrialEngineeringandEngineeringManagement,TheHongKongUniversityofScienceandTechnology, ClearWaterBay,Kowloon,HongKong,People'sRepublicofChina Received 14 December 1999; accepted 7 September 2000 Abstract Iron and steel industry is an essential and sizable sector for industrialized economies. Since it is capital and energy extensive, companies have been putting consistent emphasis on technology advances in the production process to in- crease productivity and to save energy. The modern integrated process of steelmaking, continuous casting and hot rollingSM±CC±HR)directlyconnectsthesteelmakingfurnace,thecontinuouscasterandthehotrollingmillwithhot metal¯owandmakesasynchronizedproduction.Suchaprocesshasmanyadvantagesoverthetraditionalcoldcharge process. However, it also brings new challenges for production planning and scheduling. In this paper we ®rst give a comparative analysis of the production processes and production management problems for the SM±CC±HR and the traditionalcoldchargeprocess.WethenreviewplanningandschedulingsystemsdevelopedandmethodsusedforSM± CC±HR production. Finally some key issues for further research in this ®eld are discussed. Ó 2001 Elsevier Science B.V. All rights reserved. Keywords: Iron and steel industry; Integrated process; Production planning and scheduling 1. Introduction The two oil crises in the 1970s resulted in sub- stantialpriceincreasesformineralfuelsandforced the iron and steel industry to develop energy-sav- ingtechnology.Duringthisperiod,thecontinuous casting CC) technology, which was developed in the 1950s and could save energy consumption in the production process from hot steel to slab, un- derwent a rapid growth. The casting ratio in- creased from 5.6% in 1970 to 25.2% in 1979 [1]. However, the energy-saving feature of the CC process itself is limited. In order to further reduce energy consumption, iron and steel companies in Japan proposed and implemented new techniques such as continuous casting±hot charge rolling CC±HCR), continuous casting± direct hot charge rolling CC±DHCR) and continuous casting±hot direct rolling CC±HDR) in the late 1970s. By the European Journal of Operational Research 133 2001) 1±20 www.elsevier.com/locate/dsw * Corresponding author. Tel.: +852-23587100; fax: +852- 23580062. E-mailaddress: jyliu@ust.hk J. Liu). 0377-2217/01/$ - see front matter Ó 2001 Elsevier Science B.V. All rights reserved. PII:S0377-221700)00240-X