Black & white

Barcodes are everywhere in the modern supply chain. However, ensuring that everyone who needs to read them can read them is a complex task, which involves choosing the right standards, materials and scanners.

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By  Neil Denslow Published  March 27, 2005

|~||~||~|Barcodes have long played a key role in supply chain management, tagging items through manufacturing, distribution, storage and retail processes. Coupled with an ERP system, and, perhaps, a warehouse management system (WMS) and handheld devices, barcodes can help generate a host of advantages, including realtime inventory tracking, increased productivity and lower costs. However, for a company looking to implement a barcoding system, there are a number of factors to consider in order to ensure that the black lines on the labels are readable, durable and reliable. The uses of barcodes within supply chains, and elsewhere, now cover a host of different processes. Common examples include retail point of sale (POS) transactions, tracking pallets in a warehouse, recording who borrowed which library book, labelling medical samples and tracing packages in a delivery process, to name but a few. This wide variety of applications means that an equally wide range of technologies can now be used to generate and print barcodes, and any company looking to utilise them needs to select the right system to make the most of its investments in the technology. The different factors to consider when implementing barcodes, begin with the actual barcodes themselves. They are the key to any automation project and if the wrong information is stored on the barcode, or in the wrong way, or if the barcode itself is unreadable, then the project will fail. “Without the psychical barcode in place, then a WMS [for instance] is absolutely useless,” comments Mark Jones, major account manager, LXE. “It would be difficult to find a warehouse that does not use barcodes in some areas,” adds Colin Summers, regional manager, Intermec Technologies. “The question is more how? Most of the discussions we get involved in are how do we implement it and in what areas, as well.” The essential starting point for implementing barcodes is to ask why they are being deployed and who will need to read them. The answer to this may be different for separate barcoding projects within the same organisation. At an FMCG company, for instance, pallet locations in the warehouse will only need to be read by the pickers, while barcodes on packages will need to be read by POS scanners in shops. “When implementing barcodes, the first question, especially within transportation and logistics, is: Is this my own internal barcode or do I have to create a barcode that someone else can read?” explains Timothy Cox, senior technical consultant, Intermec. “Then ask, if someone else does have to read it, is there an industry standard for those barcodes?” Because of the maturity of barcoding as a technology and its pervasiveness around the world, a number of different industry standards, or symbologies, have emerged. These symbologies state what information should be stored on the barcode and how, which then allows all of the companies in that sector to read all of the barcodes. Examples include EIA in electronics, HIBCC in healthcare, Hazmat for the chemicals sector, EAN in retail and AIAG in the automotive industry. “Whether it is Toyota or Ford, Rolls-Royce or Porsche, they use the same format, which then means customs & excise and importers can all read all the barcodes and even generate their own labels if they need to,” notes Cox. Other differences in symbologies include whether or not they are numeric or alphanumeric and whether they can support upper and lower case letters or just one of these. Different symbologies have also been designed for specific purposes, such as for being read extremely quickly or, in the case of 2D barcodes, for being produced minutely. Unlike 1D barcodes, which are seen on retail items, for instance, 2D barcodes are made up of a series of broken lines rather than just solid ones. This makes the barcode more difficult to produce, but it has the advantage of allowing a lot of information to be held in a very small space. As such, 2D barcodes are particularly used in the IT sector for labelling small components, such as microprocessors or transistors. “The real estate on those chips is very small, so you have to have very dense barcodes, which is where 2D barcodes come into play,” explains Cox. Once the symbology has been decided upon, the next factor to consider is the media for producing the barcode on. This is a key question, which relates to the purpose for which the barcode will be used, the variety of information that will be held on it, the number of labels that will have to be produced and who will produce them. Again, the simplest example of barcoding is the retail environment. A cereal manufacturer, for instance, will make thousands of boxes of cornflakes and the barcode on the actual packet will only need to hold a very limited amount of information, namely the product type and size. This will not change throughout the lifecycle of the product, so the barcode can be designed into the package and printed along with the graphics. (Alternatively, for non-packaged goods printing can be outsourced and then labels can be applied to each item.) ||**|||~||~||~|However, in other applications, the information held in the barcode will vary for each item. This could be for a variety of reasons, including the need to hold shipping information, a production date, an expiry date or because the weight varies for each unit, for instance. As such, specific barcodes will need to be printed for each item, which then means that the manufacturer, distributor or someone else will have to print individual labels and apply them to each product, package, box or pallet. This is clearly more expensive than printing multiple copies of the same label, but the greater amount of information held in the barcode will quickly produce a return on investment. It may also be possible to pre-print some items on the label that never change, such as the return address or manufacturer’s logo, and only print the actual barcode at the production line or warehouse. This helps cut costs, but more importantly, it also reduces the time it takes to print each label. If an organisation is to print its own barcode, the choice of printer will again depend upon the specific application. One type of printer will be necessary for generating thousands of barcodes per week on a production line, while a simpler model will suffice for generating a few hundred labels per week in a warehouse environment, for instance. In choosing the printer, it is also important to consider the variety of labels that will be produced. This range may require different medias for different types of labels, and it is clearly most cost effective to have one printer that is able to print on all of the different materials that will be used rather than separate units. “If you are going to print barcodes that are read for your own internal supply chain and for outside in a retail environment, can you also use the same printer to print the labels for your racking?” asks Cox. Different materials are needed for different barcodes again because of the different applications they can be used for. One good example, for instance, is whether or not the barcode will be put inside a freezer. If it is, then clearly a paper label cannot be used, as the condensation will cause it to quickly peel off. Instead, a waterproof polyester label will be necessary. At the other end of the scale, LXE was recently involved in a project with the Bahraini aluminium company, Alba, which needed to track crucibles of metal for quality assurance purposes inside a furnace heated to 1000oC. Adding to the challenge, later in the process, the same labels also needed to be read while the crucibles were being carried on the back of truck moving at 15-16 kmph. The company was able to achieve this through a combination of long range scanners, a quick-readable barcode and printing the barcode on a special heat-resistant material. RFID tags were considered for the project, but they were unable to stand the heat. “The problem [with RFID tags] was the 1000oC; everything melted,” recalls Jones. Aside from the actual material that the barcode is printed onto, the glue on the back of the label is also an issue. The choice of glue will depend on the environment that the barcode will be used in and what it will be affixed to — different glues are needed for sticking onto concrete, metal and cellophane, for instance. (Testing a variety of media before purchasing mass quantities is therefore advisable.) Aside from these basic factors, more specialised properties can be given to barcode labels for specific applications. These can range from ensuring that the label crumbles if someone tries to remove it to making the barcode impossible to remove, such as those used to trace laptop computers. The barcode may also only need to last a few minutes, if it is being used to track a piece in a manufacturing process, for instance, or it may need to last several years if it is being used by a storage company. “You can have barcodes that are designed from a cost point of view to last a few minutes or 10-15 years,” states Cox. Once the barcode is affixed, then something needs to be used to read it. A variety of different readers can be used including POS readers, handheld devices, forklift-mounted ones and a host of others. Again, the key issue is the application and getting the right device with the right capabilities for the job it will need to perform. Within a warehouse, the most common issue is the distance that the barcode will need to be read from. Readers can scan barcodes up to 12 metres away, provided that everything is set up correctly. This means using a long-range scanner and printing a larger barcode on retroreflective material. As such, this needs to pre-planned, but it is something companies often do not think about properly. “The biggest mistake we find over here… is how far away they want to read these things from,” says Jones. “Often they are trying to read a standard barcode from 11 metres [with a normal scanner] which is never going to work. So, they first need to put together what the psychical requirements are, and then based on that we can come up with a solution,” he adds. For handhelds, a wireless network also needs to be put in place that covers all areas where the devices will be used. Again, this is an issue that also often gets overlooked and one that requires detailed forward planning. “There are many cases where people say we just want [handhelds] in a specific part of a warehouse… However, six months later, we get a call saying the system is not working, and then we find they are using the devices in a completely different part of the warehouse, which was never in the original project,” comments Jones. ||**||

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