We analyze a continuous review lost sales inventory system with two types of orders—regular and emergency. The regular order has a stochastic lead time and is placed with the cheapest acceptable supplier. The emergen...We analyze a continuous review lost sales inventory system with two types of orders—regular and emergency. The regular order has a stochastic lead time and is placed with the cheapest acceptable supplier. The emergency order has a deterministic lead time is placed with a local supplier who has a higher price. The emergency order is not always filled since the supplier may not have the ability to provide the order on an emergency basis at all times. This emergency order has a higher cost per item and has a known probability of being filled. The total costs for this system are compared to a system without emergency placement of orders. This paper provides managers with a tool to assess when dual sourcing is cost optimal by comparing the single sourcing and dual sourcing models.展开更多
订单审核与投放(Order Review and Release,ORR)是一种适用于面向订单制造(Make to Order,MTO)企业的生产控制技术。生产部门接收到顾客订单后,采用ORR确定所需物料投放到车间的时间,以使订单能够按时完工。另外ORR还对车间和机器的负...订单审核与投放(Order Review and Release,ORR)是一种适用于面向订单制造(Make to Order,MTO)企业的生产控制技术。生产部门接收到顾客订单后,采用ORR确定所需物料投放到车间的时间,以使订单能够按时完工。另外ORR还对车间和机器的负荷进行限制,以降低车间库存和订单在车间内的加工时间。由此ORR考虑的是一个多目标优化问题。以往的研究中一般选取多个评价指标,分别分析后再对ORR做出一个综合定性判断,导致很难定量、客观的评价不同ORR。基于此,这里提出一个总成本公式,综合考虑了按时完工和降低车间生产时间两类目标的信息,可以对不同ORR进行全面的量化分析。在实验设计的基础上,采用总成本指标对常见ORR的实际效果进行了比较,分析结论对ORR的选择有一定的借鉴意义。展开更多
Literature review is an important component in any scientific research. In ecological and agricultural sciences, many studies have been conducted over years. With accumulation of scientific studies and published paper...Literature review is an important component in any scientific research. In ecological and agricultural sciences, many studies have been conducted over years. With accumulation of scientific studies and published papers, it is critical to summarize and evaluate these previous research findings. Different literature review methods have been applied, including traditional qualitative literature review, quantitative meta-analysis, and more recently, mega-analysis, or meta-meta-analysis. Here we briefly describe these different approaches and draw attention to the recent development of data synthesis. Several case studies were used to illustrate the application of these methods in the ecological and agricultural sciences.展开更多
文摘We analyze a continuous review lost sales inventory system with two types of orders—regular and emergency. The regular order has a stochastic lead time and is placed with the cheapest acceptable supplier. The emergency order has a deterministic lead time is placed with a local supplier who has a higher price. The emergency order is not always filled since the supplier may not have the ability to provide the order on an emergency basis at all times. This emergency order has a higher cost per item and has a known probability of being filled. The total costs for this system are compared to a system without emergency placement of orders. This paper provides managers with a tool to assess when dual sourcing is cost optimal by comparing the single sourcing and dual sourcing models.
文摘订单审核与投放(Order Review and Release,ORR)是一种适用于面向订单制造(Make to Order,MTO)企业的生产控制技术。生产部门接收到顾客订单后,采用ORR确定所需物料投放到车间的时间,以使订单能够按时完工。另外ORR还对车间和机器的负荷进行限制,以降低车间库存和订单在车间内的加工时间。由此ORR考虑的是一个多目标优化问题。以往的研究中一般选取多个评价指标,分别分析后再对ORR做出一个综合定性判断,导致很难定量、客观的评价不同ORR。基于此,这里提出一个总成本公式,综合考虑了按时完工和降低车间生产时间两类目标的信息,可以对不同ORR进行全面的量化分析。在实验设计的基础上,采用总成本指标对常见ORR的实际效果进行了比较,分析结论对ORR的选择有一定的借鉴意义。
文摘Literature review is an important component in any scientific research. In ecological and agricultural sciences, many studies have been conducted over years. With accumulation of scientific studies and published papers, it is critical to summarize and evaluate these previous research findings. Different literature review methods have been applied, including traditional qualitative literature review, quantitative meta-analysis, and more recently, mega-analysis, or meta-meta-analysis. Here we briefly describe these different approaches and draw attention to the recent development of data synthesis. Several case studies were used to illustrate the application of these methods in the ecological and agricultural sciences.
