Research On Green Scheduling Optimization Of Hybrid Flow Shop With Lot Splitting

With the proposal of "Industry 4.0",more and more countries begin to pay attention to the transformation and upgrading of manufacturing industry.The Chinese government has also put forward the "Made in China 2025" strategy,which aims to promote the high-quality development of Chinese manufacturing industry and enhance the core competitiveness of Chinese manufacturing industry.Among them,green transformation is one of the key directions.At present,carbon emission in manufacturing industry has become an important problem that affects the sustainable development of our environment and economy.As a new production mode,green industry can not only reduce pollutants such as waste gas and wastewater,but also improve production efficiency and promote industrial upgrading.On the premise of meeting the production requirements,the operation will be split reasonably,so as to improve production efficiency,reduce production costs,shorten the production cycle.This paper takes hybrid flow shop scheduling as the research object,constructs its mathematical model under the condition of considering order batch,designs GA algorithm and TLBO optimization algorithm,and compares the algorithm with examples.The results show that the designed algorithm has better solving performance,and is applied to the actual production shop of A company.It is proved that the algorithm is of great use value.Specific research contents are as follows:(1)The hybrid flow shop single objective scheduling problem(HFSP-LS)of lot splitting is studied.GA algorithm is designed based on the maximum completion time scheduling objective function and the characteristics of single objective problem.The main characteristics of GA algorithm are as follows: A three-stage chromosome coding method was designed to realize job batch,machine rate selection and sub-batch allocation.The solutions in the solution set were selected and sorted by the objective optimization function,and the chromosomal coding was selected for the new generation solution set and the optimal solution was found in the continuous iteration process.Simulation experiments are conducted to explore the effect of GA algorithm under different problem sizes.The results show that GA algorithm has a good performance in solving the single-objective hybrid flow shop scheduling problem considering lot splitting.(2)The hybrid flow shop multi-objective scheduling problem of lot splitting(MO＿HFSP-LS)is studied.The minimization of completion time and total energy consumption are taken as scheduling objectives.Aiming at the characteristics of multi-objective problems,a TLBO algorithm based on non-dominated sorting is proposed.The main features of the algorithm are as follows: Three-dimensional real number coding method is designed to realize the coding representation of lot splitting,machine rate selection and process ordering.Some newly designed examples are taken to compare TLBO algorithm with NSGA-II,PSO and IGA algorithm.The results show that TLBO algorithm can effectively solve the MO＿HFSP-LS problem based on lot splitting,which has obvious superiority.(3)The proposed two algorithms are applied to A company’s actual shop scheduling problem.Compared with the company’s original production scheme,the completion time calculated by GA algorithm was increased by 14.5%,and the result obtained by TLBO algorithm was increased by 16.51% and 7.91% respectively in terms of completion time and total energy consumption.Through the example analysis,it is proved that the proposed method is effective and can guide the production scheduling of enterprises to a certain extent.