Research On Optimization Of Production Scheduling Considering Prefabricated Building Components

At present,China is putting emphasis on the spread and development of assembly type buildings.Prefabricated construction is a new form of industrialization that transfers construction activities from the site to the off-site.It has the advantages of short construction period,low labor cost and high quality of construction,this led to an inevitable trend in the development of building industry.In the last few years,the number of PC component manufacturing enterprises is also increasing year by year.However,due to the general lack of scientific production scheduling plan for the production process of PC and production scheduling relies excessively on personal experience,the overall production efficiency of the enterprise is low and the production cost is high.Therefore,it is necessary to follow the constraints of the production process of PC component,and formulate scientific production scheduling schemes to help the production enterprises improve the production efficiency and resource utilization rate,so as to reduce the production cost and provide services for facilitating the development of prefabricated buildings in our country.This dissertation starts with the research situation and existing problems of production scheduling of prefabricated components,and discusses the optimization of production scheduling of prefabricated components.With the advancement of the production process of prefabricated components and the increasing proficiency of workers in operation,an optimization model of prefabricated component production scheduling considering workers’learning effect is proposed.The main research contents are as follows:（1）Considering the optimization goal of minimizing the total cost and minimizing the maximum service cost,the study on production scheduling optimization of prefabricated components is discussed.First,on the understanding the characteristics and theory of the production scheduling of prefabricated components,a single machine production scheduling model considering the learning ability of workers is proposed,that is,a scheduling model considering the learning effect of prefabricated components.The goal is to minimize the total production cost of prefabricated components orders.Using the pairing method,the lower bound of the problem is 2-(7(7_min,combined with the lower bound,a polynomial time algorithm is given,and the example resolution method is used to prove that this method is the best possible online algorithm.Secondly,considering the optimization research on production scheduling of prefabricated components with the objective of minimizing the maximum service cost,the lower bound of the problem is also 2-(7(7_min,and then the corresponding polynomial time algorithm is designed,which is proved to be the best possible method by stepwise analysis.（2）Study on the optimization of production scheduling of prefabricated components with the objective of minimizing delivery time.On the basis of the above research problems,we further studied the production scheduling research on the delivery time of prefabricated component orders,and also used the pairing method to obtain the lower bound of the problem as 2-(7(7_min,a polynomial time algorithm is designed for this problem,and the stepwise analysis method is used to prove that this method is the best possible.（3）The research on the production scheduling optimization of prefabricated components considering the minimum and maximum completion time of the parallel batch problem.In this research,the number of machines is8),and the prefabricated components are operated in parallel batches.The goal is to minimize the maximum completion time.A polynomial time algorithm is designed,and it is proved to be the best possible method with the method of step by step analysis.The algorithm can be well applied to the production and maintenance process of prefabricated components.For the number of curing kilns,it can be regarded as the environment of8)machines.（4）Python is used to test the four algorithms proposed in this paper to verify the feasibility and effectiveness of the online algorithm designed in this paper.According to the practical problems,a large number of data are randomly generated for targeted testing against the human factors that have learning effects on workers in the production process of prefabricated component manufacturing enterprises.For small-scale instances,the branch and bound algorithm（B&B）is used to solve the optimal scheduling scheme of the instance.For large-scale instances,the lower bound of the optimal solution generated during algorithm analysis is used to verify.The validity of the model and calculation method in this paper is verified by the data experiment.In addition,the practicability of the algorithm is verified by an example.The research results of this dissertation will help to improve the production efficiency,management effect and cost optimization of prefabricated components.The model and algorithm studied in this paper can optimize the component production scheduling,realize the load balance between production machines and workers,reasonably and effectively design the production scheduling plan,enhance production efficiency,reduce production costs,and boost the rapid development of prefabricated buildings.At the same time,it can also provide some reference for prefabricated component manufacturing enterprises to specifically implement the digital manufacturing model.