Research On Scheduling Method Of Equipment Maintenance With Complex Constraints For Iron And Steel Enterprises

Steel industry is an important part of national economy.As a typical process industry,steel industry is gradually transforming to intelligent,information,digital and high-end.Equipment is the first production factor of iron and steel enterprises.The health status of equipment directly affects the product quality and economic benefits of the enterprise.Maintenance is an important way to maintain the operating status of equipment.At present,the equipment maintenance mode generally adopted by China’s iron and steel enterprises is the point inspection and regular repair method.In order to coordinate the maintenance needs of a large number of equipment and the limited maintenance resources within the enterprise,it is necessary to reasonably arrange the maintenance tasks of each equipment to ensure the smooth development of all equipment maintenance work in the enterprise.Due to the complexity of the production process and maintenance work of steel enterprises,several complex constraints should be considered when making the equipment maintenance plan,which increases the difficulty of maintenance scheduling.In addition,the variability of the production environment of steel enterprises makes the maintenance plan need to be dynamically adjusted.The traditional manual maintenance scheduling method has strong subjectivity and blindness.It is difficult to operate and cumbersome to adjust for equipment manager in the current large-scale scheduling work with complex constraints and dynamic adjustment.All in all,the manual scheduling method can no longer meet the actual scheduling needs.Therefore,it is of great significance to realize the intelligent upgrade of the equipment maintenance scheduling method for steel enterprises.This research is derived from the optimization requirements of equipment maintenance schedule management of Bao Steel,a large domestic steel company.The main research contents of this paper are as follows:(1)Establishment of equipment maintenance scheduling modelBased on the research of the current status of equipment maintenance scheduling in steel enterprises,this paper analyzes three typical characteristics of the maintenance scheduling problem,which is large-scale,complex constraints and dynamic.Then,the constraints involved in this problem are sorted out and the optimization objectives are given.Finally,the mathematical model of equipment maintenance scheduling problem is established.(2)Research on optimized equipment maintenance scheduling methodAiming at the shortcomings of the current equipment maintenance scheduling method in Bao Steel,this paper designs a two-stage-based equipment maintenance optimization scheduling method.In the first stage,a pre-scheduling algorithm based on compound rules is used to make the pre-scheduling maintenance plan.The rule-based method can quickly obtain a maintenance plan which satisfies the constraint relationship between tasks and has relatively balanced human resource requirements.In the second stage,in order to solve the problems of unreasonable distribution of human resource requirements in the maintenance plan,an improved genetic algorithm with mutation preference is proposed to optimize the maintenance plan,and a two-stage coding method is applied to deal with the complex constraints between maintenance tasks.(3)Research on adjustment method of equipment maintenance plan in dynamic environmentConsidering the complexity and dynamics of the production environment,a hybrid rescheduling strategy combining periodic and eventdriven is designed for unexpected events that may be encountered during the implementation of the maintenance plan,and a human-machine interaction strategy is introduced to improve the flexibility of the rescheduling.Aiming at the adjustment requirements of maintenance plans triggered by dynamic events,a fast non-dominated sorting genetic algorithm with mutation preference and global archiving strategy is designed and developed to realize the dynamic adjustment and optimization of maintenance plans.(4)Development of equipment maintenance scheduling prototype systemBased on the above research,combined with the current construction status of Bao Steel’s equipment management system and actual maintenance scheduling requirements,a smart equipment maintenance scheduling prototype system with good interactive performance is developed,which provides the enterprise effective tool and platform for daily equipment maintenance scheduling work.