Study On The Optimization Of The Layout Of The Facilities In The Assembly Building Component Workshop

At present,prefabricated buildings have been widely valued in China,and the construction industrialization is also developing rapidly.However,in some assembly building projects in our country,the traditional extensive production management mode of cast-in-place building is still reflected,which to some extent hinders the promotion of construction industrialization and the development of assembly building in our country.Although assembly building has the characteristics of fast construction,low pollution and low waste,but in the long and changing life cycle of construction projects,chaotic and unscientific production activities will still cause the increase of project cost and waste of resources,thus hindering the development of assembly building.In the three main links of assembly building design,production and installation,the production cost of all kinds of prefabricated components accounts for more than half of the total life cycle cost of assembly building project,so the high production cost of prefabricated components is one of the key factors hindering the development of assembly building.However,the characteristics of factory production of assembly building bring many opportunities to apply the excellent production management methods of manufacturing industry to the construction industry.Therefore,if we can optimize all parts and links of prefabricated component production and reduce the production cost of prefabricated components,we can promote the development of prefabricated building in China to a certain extent.The layout of production workshop is the beginning of the production of products,which has been paid attention by the managers in the manufacturing industry,and is one of the key factors affecting the production cost.Reasonable workshop layout is helpful to reduce production cost and improve production efficiency.Therefore,from the perspective of production workshop layout,combined with the characteristics of prefabricated component production workshop facilities layout and prefabricated component production process,this paper uses the excellent workshop layout method in manufacturing industry for reference to reduce the production cost of prefabricated components,so as to promote the development of prefabricated buildings in China to a certain extent.Therefore,based on the perspective of economic benefits,this study proposes two objective functions of time cost and expense cost for the transportation scenario of materials in the prefabricated component workshop.First,the production cost of prefabricated components can be divided into material cost and transformation cost.Material cost mainly includes the cost of various raw materials(including concrete,reinforcement,etc.),the cost of production facilities purchase and maintenance(concrete mixer,production mold,etc.),and transformation cost mainly refers to the cost of various raw materials converted into prefabricated components through production facilities and labor Expenses,such as labor cost,energy consumption cost and transportation cost inside the workshop.As the cost of raw materials and production facilities included in the material cost belong to the necessary cost,considering the quality of prefabricated components,it is difficult to optimize and reduce,so only some transformation costs incurred in the production process of prefabricated components of prefabricated buildings can be considered.Secondly,in the process of converting prefabricated components from raw materials to finished products,materials need to be transported between various facilities,and these transportation links need to consume time.If the layout of facilities is not reasonable,a lot of time will be wasted,thus increasing the production cost.Therefore,under the premise of considering cost,time cost also needs to be considered.The problem studied in this paper consists of two objective functions,which belong to the multi-objective optimization problem.Therefore,NSGA-II algorithm is adopted in this paper.This algorithm can solve the multi-objective problem accurately and quickly,and is one of the most excellent multi-objective problem solving algorithms at present.In addition,this paper uses an integer coding method with line feed mechanism,which is easier to understand.In addition,this study takes the ready-made concrete prefabricated component workshop as an example to optimize the design of production facilities in the workshop,and the optimization results verify the feasibility and applicability of the proposed model.The optimized workshop can reduce the cost of material transportation in the production process of prefabricated components.The innovation of this paper lies in:first,from the perspective of reducing the assembly cost,combining the layout characteristics of the prefabricated component workshop,referring to the excellent method of workshop layout in manufacturing industry,the corresponding layout method is proposed;second,considering the two objectives of material transportation cost and material transportation time in the prefabricated component production,and combining the integer of genetic algorithm Thirdly,NSGA-? algorithm,which is improved by genetic algorithm,is used to find the pre Pareto optimal solution between cost and time targets,and the layout scheme represented by Pareto optimal solution is analyzed.