Mixed-model assembly lines enable a flow-oriented mass production of individualized products such as cars. The most investigated operational decision problems in this domain are the sequencing problem, which plans the initial sequence of cars launched down the line, and the resequencing problem, which alters a given car sequence by applying resequencing buffers. This dichotomy of existing research neglects a third, even more short-term decision level: launch control under real-time conditions. In large automotive assembly lines unforeseen disturbances are rather the norm, so that one of the most important decisions to maintain a smooth and error-free production flow is the continuous launching decision of the next car model released from the central chassis storage system into final assembly. The launching decision in every cycle is made in a central control room (or leitstand) and has to consider the current state of the assembly line itself, with all potential time delays and defects in any assembly station, along with all part feeding processes under real-time conditions. This paper provides an integrated solution approach for real-time launch control that applies sophisticated optimization procedures considering both the workflow along the assembly line and its impact on part feeding processes. We test our real-time approach in a simulation study and compare it with alternative launching approaches. Our results show that sophisticated real-time optimization clearly outperforms its competitors. Furthermore, an integrated approach including part feeding aspects can considerably reduce safety stocks of parts within workstations.

混合模型装配线可实现个性化产品（例如汽车）的流程导向型批量生产。该领域中研究最多的操作决策问题是排序问题和重新排序问题，排序问题计划着下线的汽车的初始序列，而重新排序问题则通过应用重新排序缓冲区来改变给定的汽车序列。现有研究的这种二分法忽略了第三个甚至更短期的决策层：实时条件下的发射控制。在大型汽车装配线中，不可预见的干扰是常有的事，因此，保持平稳无误的生产流程的最重要决定之一就是从中央底盘存储系统释放到最终装配的下一款车型的持续启动决定。 。每个周期的启动决定都是在中央控制室（或站台）中做出的，并且必须考虑装配线本身的当前状态，所有装配工位中的所有潜在时间延迟和缺陷以及实际情况下的所有零件进给过程时间条件。本文提供了一种用于实时启动控制的集成解决方案方法，该方法应用了复杂的优化程序，同时考虑了装配线上的工作流及其对零件进给过程的影响。我们在模拟研究中测试了我们的实时方法，并将其与替代发射方法进行了比较。我们的结果表明，复杂的实时优化明显优于竞争对手。此外，包括零件进给方面的集成方法可以大大减少工作站内零件的安全库存。