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| The EPCglobal Network |
- How does a computer act on information about a product?
- The whole point of automatic identification is to take people out of the loop, to enable computers to gather information and act on it. For that to happen, computers must be able to not just identify a product, but also interpret some basic information about it. To make this possible, the Auto-ID Center started to develop a new computer language called the Physical Markup Language. PML is based on the widely accepted eXtensible Markup Language (XML), which is used to describe common types of data (addresses, dates, invoice numbers and so on) and transactions (purchases, requests for quotes and so on) in a way computers running different proprietary applications can understand. PML files will be stored in the EPC Information Service (once called PML servers). EPC Information Service will reside on computers distributed across the Internet. (The Object Name Service, described above, points computers to data about products stored in the EPC Information Service.) Some information about each product will be stored in a PML file, such as a product's name and broad category (soft drink, auto part, clothing and so on), when it was made and where, its expiration date, its current location, even its current temperature, if that's important. PML files will provide information to existing enterprise applications or new yet-to-be developed applications. The PML file could contain instructions for where a pallet should be shipped. It could contain instructions for a point-of-sale display to lower the price of an item when its expiration date approaches. Or it could contain instructions for how long your microwave needs to cook a particular brand of frozen pizza.
- How do you avoid having all this data about individual products overload existing networks?
- The Auto-ID Center created software technology called Savants to manage and move information in a way that doesn't overload existing corporate and public networks. Savants use a distributed architecture, meaning the software runs on different computers distributed through an organization, rather than from one central computer. Savants are organized in a hierarchy and act as the nervous system of the new EPC network, managing the flow of information. At the edge of the network, Savants gather data from readers. They pass on only relevant information to existing business applications, such as which products are about to expire. A Savant running at a distribution center might determine when product needs to be reordered from manufacturers, and so on. EPCglobal is phasing out the name "Savants". Middleware companies have developed commercial products that do what Savants were designed to do.
- How do Savants work?
- The Auto-ID Center designed Savants to act as the nervous system of the network. Savants were designed to be different from most enterprise software in that it isn't one overarching application. Instead, Savants were designed as a distributed architecture and the software would be organized in a hierarchy to manage the flow of data. The vision was that there would be Savants running in stores, distribution centers, regional offices, factories, perhaps even on trucks and in cargo planes. Savants at each level would gather, store and act on information and interact with other Savants. This function is being absorbed into different forms of RFID middleware.
- Why were Savants needed?
- There are tasks that needed to be performed in order for the EPC network to work as envisioned by the Auto-ID Center. At the time, no middleware could handle these tasks. But companies have taken the concept and incorporated many of the tasks envisioned for Savants in their middleware products. Among the tasks are:
• Data smoothing: Software at the edge of the network-those attached to readers-will smooth data. Not every tag is read every time, and sometimes a tag is read incorrectly. By using algorithms middleware is able to correct these errors.
• Reader coordination: If the signals from two readers overlap, they may read the same tag, producing duplicate EPCs. Software must be used to analyze reads and delete duplicate codes.
• Data forwarding: At each level, middleware has to be set up to filter information and pass on only necessary information to an enterprise application. For instance, middleware in a cold storage facility might forward only changes in the temperature of stored items that exceed certain thresholds.
• Data storage: Existing databases can't handle more than a few hundred transactions a second, so another job of the middleware is to maintain a real-time in-memory event database (RIED). In essence, the system will take the EPC data that is generated in real time and store it intelligently, so that other enterprise applications have access to the information, but databases aren't overloaded.
• Task management: Essentially, middleware is customized to manage data and execute commands. For instance, middleware running in a warehouse might be programmed to alert the manager when the number of pallets of a particular product drops below a certain level.
- What is the Object Name Service?
- The Object Name Service (ONS) is an automated networking service similar to the Domain Name Service (DNS) that points computers to sites on the World Wide Web. When an interrogator reads an RFID tag, the Electronic Product Code is passed to middleware, which, in turn, goes to an ONS on a local network or the Internet to find where information on the product is stored. ONS points the middleware to a server where a file about that product is stored. The middleware retrieves the file (after proper authentication), and the information about the product in the file can be forwarded to a company's inventory or supply chain applications.
- Who will maintain the ONS?
- EPCglobal has awarded VeriSign a contract to maintain the root ONS directory. But the Object Name Service will handle many more requests than the Web's Domain Name Service. Therefore, companies will likely maintain ONS servers locally, which will store information for quick retrieval. So a manufacturer may store ONS data from its current suppliers on its own network, rather than pulling the information off the Web site every time a shipment arrives at the assembly plant. The system will also have built-in redundancies. For example, if a server with information on a certain product crashes, ONS will be able to point the RFID middleware to another server where the same information is stored.
- What is Physical Markup Language?
- The Electronic Product Code identifies individual products, but all the useful information about the product would be written in a new, standard computer language called the Physical Markup Language (PML). PML is based on the widely accepted eXtensible Markup Language (XML). Because it's meant to be a universal standard for describing all physical objects, processes and environments, PML will be broad and will cover all industries. It will provide a common method for describing physical objects and will be broadly hierarchical. So, for instance, a can of Coke might be described as a carbonated beverage, which would fall under the subcategory soft drink, which would fall under the broader category food. Not all classifications are so simple, so to ensure that PML has broad acceptance, EPCglobal is relying on work already done by standards bodies, such as the International Bureau of Weights and Measures (Le Système International d'Unités - SI) and the National Institute of Standards and Technology in the United States.
- What types of data will be stored in the PML file?
- In addition to product information that doesn't change (such as material composition), PML will include data that changes constantly (dynamic data) and data that changes over time (temporal data). Dynamic data in a PML file might include the temperature of a shipment of fruit, or vibration levels from a machine. Temporal data changes discretely and intermittently throughout an object's life. One example is an object's location. By making all of this information available in a PML file, companies will be able to use information in new and innovative ways. A company could, for instance, set triggers so the price of a product falls as its expiration date approaches. Third party logistics providers could offer service-level contracts indicating that goods will be stored at a certain temperature as they are transported.
- Where will all these PLM files be stored?
- PML files will be stored in online databases that will be part of something called the EPC Information Service (formerly called a PML server). The EPC Information Service is a distributed system of managing EPC data across many computers connected to the Internet. One element of the service is to manage who has access to different types of company data. So a company might provide full access to some business partners, access to shipping information to its logistics providers and inventory data only to its retail partners. Companies may maintain their own EPC Information Service computers or outsource this to companies such as VeriSign.
- Will my company have to replace our entire bar code infrastructure to take advantage of the Electronic Product Code?
- EPCglobal is promoting the Electronic Product Code as the next standard for identifying products. It is trying to create a migration path for companies to move from established standards for bar codes to the new EPC. To encourage this evolution, it has adopted the basic structures of the Global Trade Item Number (GTIN), an umbrella group under which virtually all existing bar codes fall. It is envisioned that companies will maintain their bar code systems and add new EPC infrastructure.
- What can the EPC network do that existing bar code systems can't do?
- Bar codes are a line-of-sight technology. That is, a scanner has to "see" the bar code to read it. That means people usually have to orient the bar code towards a scanner for it to be read. Also, if a bar code label is ripped, soiled or falls off, there is no way to scan the item. Radio frequency identification, by contrast, doesn't require line of sight. RFID tags can be read as long as they are within range of a reader. And since radio waves pass through plastic, tags can be protected from damage. Because RFID tags can communicate with readers without line of sight in most cases, RFID also has the potential to reduce out of stocks. Studies show that, on average, products are not on the store shelves 7 percent of the time. Every time a customer leaves a store without buying what they came for because it wasn't on the shelf, the retailer and the manufacturer lose out. RFID has the potential to dramatically reduce out of stocks by providing real-time visibility into what's on the store shelves. It also has the potential to dramatically reduce theft by alerting store employees to unusual activity at the shelves. It may also reduce employee theft, counterfeiting, administrative errors, and mass recalls. And there are some unique benefits associated with the ability to track individual items. Down the road, RFID tags have the potential to be combined with sensors to monitor the status of the product. Sensors might, for instance, detect that a shipment of milk was left in a warm environment for a period of time. Computer systems could then bring forward the milk's expiration date to account for the lack of refrigeration. Sensors might also reveal whether food products have been spoiled or tampered with. Once a company has installed the infrastructure to take advantage of tracking products over the EPC network, other capabilities can be added cost effectively.
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