如今，了解白天和黑夜的材料在哪里以及他们在做什么是盈利制造的一部分。因此，像密歇根州米德兰市的Dow Kokam这样的世界一流制造商一直在继续投资于最新技术，以在整个供应链中跟踪其库存。
For example, the manufacturer of cells for automotive batteries recently put a Siemens Simatic IT manufacturing execution system (MES) at the heart of its inventory control. The move took advantage of libraries of best practices developed by the automation vendor over the years, including those for streamlining integration with other software. Through the communications channels established by these tools, the MES accesses data in the company’s enterprise resource planning (ERP) system and other software.
“The ERP tracks the raw materials on hand, and the MES traces everything [produced], back to the raw materials,” explains Chris Wunderly, senior software engineer atHyla Soft Inc.（www.hylasoft.com），基于芝加哥的系统集成器，该集成器安装了基于MES的跟踪系统。“ ERP系统通常对订单和库存有非常广泛的概述 - 工厂中有多少材料以及生产多少产品。但是，他们不一定有详细的家谱，可以追溯到所有投入。”那就是MES的工作。
电池制造商的流程自动化管理器Sungsoo Oh说，道尔·科卡姆（Dow Kokam）的新MES从其现场到达现场的制造过程中跟踪了所有原材料。该软件还验证了操作员是否正在自动化机械上分配正确的材料。当操作员将材料加载到队列中时，他们会用手持设备扫描容器上的条形码，因此软件可以执行必要的检查。如果操作员错误地加载了错误的容器，则机器将拒绝运行。
The MES uses quality-control data in a similar way through a link to a laboratory information management system (LIMS). In the course of producing lithium-ion batteries, for example, the process calls for collecting samples at various points of production and sending them to a laboratory to check key performance indicators (KPIs). As in the staging of materials, the operators and technicians use barcodes and handheld devices to keep track of each sample. Once the test is completed, the LIMS returns the results to the MES, which links them to the specific batch and releases that batch to the next operation only if the KPIs are within the specified control limits.
同时，另一个软件，一位历史学家，定期收集和档案KPI为生产设备收集和档案。MES产生的家谱通过整个过程追踪材料，而历史学家则定期跟踪设备的状态。“历史学家包含有关设备的情境化信息，” Hyla Soft的Wunderly说。“使用时间戳记，用于创建很多时间，您可以在出现问题时使用历史学家中的数据进行分析。”
Why track with MES?
The strategy of making the MES the hub of the inventory tracking system has at least two important benefits for Dow Kokam, according to SungSoo Oh. First, if quality-control checks uncover a developing problem, the data help the engineering staff to conduct a root-cause investigation and pinpoint the problem. Second, if a problem serious enough to trigger a recall were to slip through undetected, the genealogy would help focus the effort on the affected products only, thereby expediting the recall and containing its cost.
The company already knows the entire genealogy of each battery cell—from the original lots of chemicals and other raw materials to the machines that processed them and the values of the KPIs during production. “So just reading the barcode tells you not only what went into a particular cell, but also all other cells made from the same ingredients or on the same equipment,” observes Wunderly at Hyla Soft. “Once you figure out what the problem is, you can find out exactly which products were affected.”
Getting these results, however, requires a thorough understanding of the process and careful planning to skirt the technical challenges. “Although plants are becoming increasingly more automated, sometimes older equipment doesn’t have a way to report key information, such as quantities or type of material,” notes Wunderly. Machines can also give inaccurate readings for reasons as simple as the sensors or a measurement technique itself is inadequate for the task at hand.
By tending to such details, Stora Enso was able to rectify the problem when the Helsinki-based paper company received a complaint from a food processor about some container board produced at its Imatra Mill in Finland. Because governmental regulations and industry standards require being able to trace the geology of all materials that come into contact with food, the mill had contracted ABB Ltd. to enhance its ability to do so.
基于苏黎世的自动化供应商安装了MES，该MES从其组成纸浆和其他化学品以及包装材料的每片卷或托盘的家谱进行追踪。除了跟踪生产中使用了哪些机器和卷轴外，该系统还将每个批次链接到相关的质量控制测试以及在生产过程中记录的任何符号。
结果，客户服务能够在数小时内进行故障排除和解决投诉，而不是花几天时间。“更重要的是，它使他们能够确定是否受到任何其他客户的影响，并在这些问题成为问题之前积极解决这些问题。”ABB Inc.（www.abb.com）in Wickliffe, Ohio.
利用更好的工作流程
The success that that users like Stora Enso and Dow Kokum have had in tracking inventories with an MES is due in part to advances in workflow management. “The ease of creating workflows today means that it has become much easier to tailor systems to organizational needs than to modify operations to fit a specific system,” explains Leroux.
“It wasn’t so long ago,” he adds, “that the only companies successful in implementing an ERP system were those that modified their operations to cater to the system.” These users paid the high implementation costs that people still talk about. Even today, ERP systems typically will not conform to a particular manufacturing operation as easily as will an MES or other software for managing manufacturing operations, according to Leroux.
Despite the difficulties that existed in the past and still exist in some industries, ERP systems can be quite useful in tracking inventories and tracing lots over a long supply chain. “Most ERP systems have modules designed to manage this data,” notes Wolfgang Kratzenberg, marketing manager for industrial identification atBalluff Inc.(www.balluff.us)在佛罗伦萨，肯塔基州。
>>条形码和RFID：在同一团队中。点击这里阅读这两种技术如何共同努力比竞争更多。
Some companies, however, are finding that they must jump a different kind of hurdle before they can use ERP systems to trace material through their entire supply chains: The capability often exists in loosely connected islands of automation. “Today, the degree to which material is tracked depends on the industry and organizational maturity,” says Leroux at ABB.
他继续说：“此外，根据'标准'使用而非实际消费，在ERP系统中积累了有关原材料使用情况的信息。”“在许多情况下，物质使用可能是基于生产人员直接每天甚至每周直接进入ERP系统进行的每日库存更新。因此，尽管着重于将ERP系统与过去十年制造的制造业联系起来，但我们仍在实施这些解决方案的早期。”
即便如此,Leroux越来越感兴趣产品开发报告loping them. In one case, a manufacturer asked his group at ABB for help in getting its ERP system to transmit production orders to its automation system, as well as in getting production to respond with appropriate messages as it finished them. “When the engineers saw that it was fairly straightforward to integrate manufacturing with ERP, they started to ask what other information could be exchanged,” Leroux recalls.
他们的查询导致将原材料的使用实时与ERP系统进行了集成，这一项目导致库存成本降低。随后的讨论还导致更好地报告制造业中订单的状况。有了这些知识，用户可以在实际需要时安排运输，并大大降低其转会成本。
A tale of two methods
这些ERP系统，混乱和其他较小规模的系统属于Balluff的Kratzenberg称为管理库存数据的集中方法。顾名思义，此类别中的软件将数据存储在中心位置，因此许多人可以从各个位置访问它们。它通常与条形码技术和仅阅读射频标识（RFID）一起使用，以将单个项目链接到中央系统。
“Advances, however, in mobile device technology have allowed processing and storage to occur locally, or decentralized on the individual handheld units,” says Kratzenberg. “It is still more common, though, to transfer the data from a handheld to a centralized location at a later time.”
Hence, the more common approach to this second, decentralized method is to store the data on a read-write RFID tag. Each station reads and writes the pertinent information to the tag as the work-in-process advances through production. “In a non-networked environment, a decentralized data system is ideal for sharing traceability information by interconnecting islands of automation,” says Kratzenberg.
在Autoliv Inc.，这种方法为基于斯德哥尔摩的公司为汽车行业生产的安全设备执行了质量标准。由于其产品可能意味着世界各地驾驶员生与死之间的差异，因此其制造运营将RFID标签附加到制作过程中，以防止错误并证明其产品符合规格。
As a workpiece undergoes in-process inspections to verify the efficacy of individual manufacturing operations, the system writes the appropriate results directly on the tag. As long as the workpiece passes each inspection, the subsequent operation will accept it and go about performing its task as usual. If, however, the workpiece fails an inspection, subsequent operations will refuse to work on it. The workpiece must be removed for rework or disposal.
“Every operation is tracked along the way and documented on the tag, providing a detailed history,” says Kratzenberg. This data provides the necessary documentation that the product was produced to specification.
一些制造商也给他们的标签production machinery and tools, both as set-up aids and as usage and maintenance logs. Consider what they can do for a stamping press. “Not only can an RFID tag identify the correct die for the job, but it also can hold the operating parameters for the die, preventing human input errors,” says Kratzenberg. Tags on the tool can also record the number of hits and let technicians know when it is time to pull it for preventive maintenance. A repair technician can sign off on service performed directly on the tag, and management can identify who performed repairs or service and determine when it was done.
Although the centralized and decentralized methods are different, they are not mutually exclusive of one another. Manufacturing organizations often deploy them both—often to their great advantage—to let them always know where their inventories are.
