Research On Integrated Scheduling Optimization Of Prefabricated Building Production-transportation

With rising labor costs and increasingly prominent resource and environmental issues,the construction industry urgently needs to transform to sustainable development and industrialized buildings.Prefabricated buildings can shorten construction time,reduce energy consumption,improve construction quality,and reduce pollution and labor.Although prefabricated buildings have many advantages,the development of prefabricated buildings has not met expectations,mainly because there are problems such as complex scheduling,insufficient integrated management level,and frequent uncertain events in the construction process of prefabricated buildings.Therefore,from the perspective of prefabricated building component suppliers,this thesis establishes a prefabricated building production-transportation integrated scheduling model based on installation time windows under certain and uncertain conditions.This thesis aims to improve the efficiency of prefabricated building resource allocation,and Improve the ability to deal with uncertain events during the construction of prefabricated buildings.This thesis studies the integrated scheduling optimization problem of prefabricated building production-transportation under certain and uncertain conditions.Under certain conditions,the objective function of minimizing the total cost is established.In the production stage,the traditional permutation flow shop scheduling model is used,and factors such as process interruption,parallelism,and non-working hours are considered.In the transportation stage,considering factors such as large components,limited installation space,and the load of transportation vehicles is much smaller than the order quantity,the transportation process is modeled as JIT on-time delivery and batch delivery.A segmented chromosome based on component production sequence and transportation sequence is designed.Through adaptive greedy tabu genetic algorithm(referred to as AGTGA)in the adaptive crossover and mutation,destruction,taboo,reconstruction operators to avoid falling into the local optimal solution of the genetic algorithm,better balance the local and global Search to reduce the number of invalid searches.And through the Taguchi experiment to determine the optimal combination of AGTGA parameter values,using27 examples to test the effectiveness and superiority of AGTGA.In order to avoid insufficient productivity of a single assembly line and further enrich the application scenarios of the algorithm,the production mode of single supplier and multiple assembly lines under uncertain conditions is studied.Triangular fuzzy numbers are used to represent the uncertainty of production processing time and transportation time,and trapezoidal fuzzy numbers are used to represent the uncertainty of installation time window.And based on the hierarchical relationship between multiple assembly line decisions,a two-level optimization model of order assembly line allocation and single assembly line production-transportation integrated scheduling is established,and the two-level optimization model based on AGTGA is used to solve it.In the upper-level optimization,the assembly lines are assigned to component orders,the order assembly lines allocation scheme with the lowest total cost of multiple pipelines is calculated.In the lower-level optimization,the fuzzy pessimistic satisfaction degree considering the risk preference of the decision maker and the anti-risk ability is introduced,and the component production and transportation sequence scheme with the largest fuzzy pessimistic satisfaction degree under the single assembly line is calculated.The effectiveness of AGTGA-based twolevel optimization solution for prefabricated building production-transportation integrated scheduling under uncertain conditions is tested by using a case.The cost of a single assembly line under certain and uncertain conditions is further analyzed,and the relationship between model parameters(vehicle load,transportable vehicles,and installation time window width)and cost is discussed,and effective suggestions are provided for the scheduling management of prefabricated buildings.Under the multi-subject and multi-stage characteristics of prefabricated buildings,the production-transportation integrated scheduling optimization of prefabricated buildings coordinates the scheduling scheme of the production and transportation stages of prefabricated buildings according to the component installation time window,and provides a scientific and reasonable solution for the prefabricated building scheduling problem.Scheduling strategy to further improve the construction efficiency of prefabricated buildings.