随着经济社会的不断发展和人们生活水平的日益提高，人们对于汽车产品的需求更趋向于个性化和多样化。传统刚性单一型的生产线难以满足快速变化的市场需求，具备柔性的混流生产线应运而生。所谓柔性化即生产线能同时生产不同品种的产品，又可以随着市场需求的变化而调整共线的各产品之间的相对比率。柔性化生产方式不但能提高企业的生产效率，降低成本，更提高了企业面对市场需求变化的响应速度，因而被广泛应用于汽车生产中。但柔性化的生产方式也带来一个难题，即混流生产线平衡问题。混流生产线的平衡是将所有装配作业合理地分配到各个工位。混流装配线平衡的质量直接影响企业的生产效率。本文以M公司的总装生产系统为研究对象，以A车型产能瓶颈为背景。为短时间内提升A车型的产量，决定将A车型引入到D车型现有的总装生产线上。因为不同车型装配工艺有一定差异，如何平衡混合车型的装配线工艺以达到最大的生产效率成为摆在工艺人员面前的一个问题，也是本文研究的重点。本文首先总结了以往学者对装配线平衡的研究。随后对单一型装配线进行研究并给出了线平衡结果的评价指标，并详细阐述了用综合优先关系图将混流装配线转化为单一型装配线的方法。随后对启发式算法进行了研究。建立M公司混流装配线的优先约束关系以及综合作业时间表，并运用启发式算法对M公司的混流装配线进行求解。针对一个工位分配多名操作工的方法进行了探索。线平衡结果的评价指标表明启发式算法在求解特定生产线上有较好的效果。通过对线平衡方案的分析表明，运用启发式方法求解混流生产线规划初期的线平衡问题有较好的效果，为后续的持续改善提供了良好的基础。为工艺人员提供了一种可行的求解方法。
As the society economy develops continually and people’s income grows increasingly, people tend to be more and more individual and diverse when choosing vehicle product. It is harder for the traditional rigid single production line to meet requirement of fast changing market, this provide the earth for the flexible mixed-model production line. The so-called flexible production means one production line is capable to produce different products simultaneously, the volume rate of different product can also change in a certain range. Flexible production line not only improves the efficiency and reduces the cost of labor, but also makes the company react faster to the changing market. It has already been widely used among automobile manufacturing and assembly. But flexibility also brings one problem that is Mixed-model Production Line Balancing problem.Mixed-model Production Line Balancing means to allocate all the assembly tasks to each station in a reasonable way. The quality of the line balancing has direct influence on the efficiency of the company. This paper studied the assembly production system of M company, car model A has already reached its maximum volume and facing the bottle neck as background. In order to increase the production volume of car model A in a short period, the company decided to implement model A into the assembly shop which D is produced currently. Because of the process deviation between different model, all the process engineers are facing the fact that how to make the mixed line balancing to reach the maximum efficiency, this is also the main focus of this paper.This paper summarized previous research on mixed model assembly line balancing firstly. Then it conducted a research on single model assembly line and come up with a set of evaluation method for the assembly line balancing. Afterwards it detailed explain how to transform mixed-model assembly to single model assembly line using combined precedence diagram. Hence, heuristic algorithm was very explained in very detail. By setting up the combined precedence diagram and combined working step time for M company example line, we are able to use heuristic algorithm to solve the line balancing problem. In addition, this paper also went deep dive into the method of distributing more than one worker to a station. Finally the evaluation shown that heuristic algorithm is suitable for some certain mixed-model production lines.The result shows heuristic algorithm is capable to solve the mixed-model production line balancing problem in the planning phase and the solution provided a good basement for the future improvement. Another benefit was that it provided a method for solving mixed-model assembly line problems.
