混合型生产企业的自制/外包生产调度优化策略研究

Outsourcing has become a popular practice that many manufacturers entrust subcontractor with some operations of an entire process instead of managing all process directly. Well-utilized outsourcing can reduce total costs and make supply capacity more flexible. While a manufacturer can benefit from outsourcing, the potential maximum benefit cannot be achieved unless there is an efficient and effective production schedule that can cope with the complexity of outsourcing. The problems to be studied in this research project are about the mixture scheduling of the in-house production, the subcontractor's production, as well as their coordination for hybrid process industry. Considering the continuous and discrete characteristics, resource and time constraint hybrid Petri net is developed to describe both the discrete event and continuous dynamic material flows in hybrid production process system. Based on analysis of the bottleneck resource revealed, different forms of outsourcing opportunities are studied: some subcontractors may be able to provide production for several operations in hybrid process; some subcontractors may be dedicated to the operation in one stage only; the manufacturer may fully outsource all jobs to a subcontractor for one operation, or partially outsource a subset of the jobs. Considering the logistic issues between the subcontractor and the in-house shop under the different situations of outsourcing, a schedule is established to make not only the sequencing decisions in conventional scheduling problems, but also new dimension of decisions for job allocation. We present models, whose objective is to minimize the sum of weighted earliness/ tardiness penalties and total outsourcing costs. Given the problems are of NP-hard, hybrid hierarchy heuristic algorithms are suggested, whose effectiveness can be well tested and improved throuth computation experiments and application research in real company. Our operational level results would provide important information for the strategic decisions such as the choice of a particular form of outsourcing.

外包是帮助制造企业降低生产成本及构建柔性供需关系的有效手段。然而，外包资源能否得到合理的利用，很大程度上依赖于企业在不同外包模式下生产调度优化方案的制定。为此，本项目以代表性的混合型生产企业为对象，研究不同外包资源运用情形下的自制/外包生产调度优化策略问题。首先从混合流程的复杂动态性特征分析出发，运用混杂网络流理论构建资源及时间约束的混杂Petri网模型，描述资源状态及物料能量流；在运用瓶颈资源约束理论对关键工序识别的基础上，分别在单工序外包及多工序并行外包两种模式下，分析其对自制系统物料衔接及调度要求等方面的影响，采用模糊规划方法构建多目标调度优化决策模型，并设计相应的混合元启发式递阶算法；最后通过实际企业的应用研究，对理论方法进行实践验证。项目从运营角度的自制/外包生产调度优化研究，是对传统自制系统作业调度的延展，为企业后续优势产能资源的配置及外包模式的选择等战略决策提供有价值的参考。

外包是帮助制造企业降低生产成本及构建柔性供需关系的有效手段。然而,外包资源能否得到合理的利用,外包与自产环节是否能良好地衔接，很大程度上依赖于企业在不同外包模式下生产调度优化方案的制定。为此,本项目以代表性的混合型生产企业为对象,考虑离散型加工环节与连续型加工环节并存，存在不同加工单位和加工工艺要求的复杂环境下，研究不同外包资源运用情形下的自制/外包生产调度优化策略问题。首先，从混合流程的复杂动态性特征分析出发,运用混杂网络流理论构建资源及时间约束的混杂 Petri 网模 型,描述资源状态及物料能量流;在运用瓶颈资源约束理论对关键工序识别的基础上,区分不同的外包模式与外包类型；分别在单工序外包（离散装配环节／批处理连续环节）及多工序并行外包两种模式下,分析其对自制系统物料衔接及调度要求等方面的影响,考虑与外包任务个数相关的外包成本折扣，构建包括完工时间及总成本在内的多目标调度优化决策模型,并设计相应的混合元启发式递阶算法，而后通过对比和测试，改进决策模型，通过引入“打包”的概念优化启发式规则算法;最后在存在多个外包产线和外包商的情况下，探讨了定时长定投料速率条件时，从最大产出和效益角度出发的多产线生产调度优化仿真研究。项目在解决上述调度优化决策问题中探索了多种求解方法，并将改进的算法应用于包括产线布局、机器配置等相关的多种生产调度优化中，充实了决策优化方法的研究。项目从运营角度的自制/外包生产调度优化研究,是对传统自制系统作业调度的延展,为企业后续优势产能资源的配置及外包模式的选择等战略决策提供有价值的参考。