Multi-objective Optimization Research On Production Scheduling Of Prefabricated Building Components

As an important means of transformation and upgrading of China’s construction industry,assembly construction production mode has been widely used and promoted.The production of prefabricated components is the core link in the construction of prefabricated buildings,and its scientific schedule has an important impact on the overall project schedule,and affects the costs and benefits of prefabricated building projects.At present,the production schedule of prefabricated components mainly relies on the experience of dispatchers.Systematic,scientific and continuous optimization are often insufficiently considered,and it is easy to cause problems such as the difficulty of component production to match the construction schedule,the increase of construction costs,and the decrease of production efficiency.The scientificity and rationality of the prefabricated component production schedule arrangement is conducive to the improvement of the production and transportation efficiency of prefabricated components,which is of great significance to the development of prefabricated buildings.This article first analyzes the production process and technological characteristics of prefabricated components,and builds a production scheduling model for prefabricated components based on traditional flow shop production scheduling theory.The production scheduling model system considers the constraints of the type and quantity of molds,the number of maintenance kilns,buffer space,working time,etc.,as well as the influence of worker load on the processing time of each process of the component,and establishes a dual-objective production scheduling optimization model with the goal of minimizing production completion time and minimizing penalty costs is established.Secondly,based on the mathematical model of component production scheduling,the non-dominated genetic algorithm with elite strategy is used to optimize the scheduling scheme.According to the characteristics of component production,the coding and decoding methods are designed,and the algorithm realization process of component scheduling is analyzed.By discussing the non-dominated sorting process of the algorithm and the elite retention strategy,the genetic operation method suitable for prefabricated components is selected to implement the algorithm of the scheduling model.Finally,a case study of the production process of prefabricated components in a prefabricated construction project in Beijing is carried out.The production scheduling optimization of a batch of prefabricated components in this case is calculated by MATLAB software,and multiple groups of Pareto components were obtained.At the same time,the influence of each constraint on the optimization goal was analyzed.The application results of this case show that the multi-objective optimization model of prefabricated component production scheduling established in this paper can provide an effective solution for multi-objective optimization of prefabricated component production scheduling,which can meet the needs of shortening the construction period and reducing costs.Compared with the existing research on the optimization of the production scheduling of prefabricated building components,this paper further improves the constraint conditions of the prefabricated component production process,and considers the influence of worker load on the processing time of prefabricated components.