The wireless factory: increase productivity, reduce costs
Patrick A. Toensmeier
One of the strongest growth areas in manufacturing is the wireless factory. The system uses a wireless local area network (WLAN) within a plant and portable devices like PDAs (personal digital assistants), cell phones, and notebook computers to provide real-time operational data. Equipment advances in recent years and standardization of wireless specifications have enabled many manufacturers to increase productivity and reduce costs.
Wireless devices have for years been part of manufacturing, usually in standalone applications like automated work cells, robot-guided vehicles, overhead cranes, and barcode scanners. The wireless factory is different in that it is a data-transmission system that extends throughout a plant and replaces wired devices like computers, sensors, and telephones, and minimizes or eliminates the need for paper. Using handheld devices to transmit, access, and store real-time data on materials management, production runs, maintenance, order volume, and shipping substantially increases the speed with which personnel identify and correct problems and plan for upcoming needs.
Wireless installations are primarily confined to large plants in industries like automotive, electronics, pharmaceuticals, and food and beverage processing. Automakers BMW, Toyota, and AM General, which builds the Hummer SUV, aircraft manufacturer Boeing, and chipmaker Intel are among companies with the technology. (Intel claims a 25% reduction in material waste in two New Mexico fabrication plants as a result of the technology.) But as the benefits of wireless become evident, it is being adopted by more factories, including smaller plants (those with fewer than 500 employees).
The technology is rare among plastics processors, mostly because it is best suited to downstream operations like materials and production management, and to lean manufacturing, as opposed to process control. Yet many believe it is only a matter of time until processors adopt the wireless factory for its benefits in productivity, economy, and competitiveness. “Plastics companies whose operations include packaging or just-in-time delivery are prime candidates,” says Kevin Bernier, director of plant intelligence solutions for GE Fanuc Automation Americas Inc., Charlottesville, Va.
One development expected to influence the growth of the wireless factory is RFID (radio-frequency identification), a wireless technology for tracking data (encoded on special tags) that is being championed by retail giant Wal-Mart and other large companies in the U.S. and elsewhere. Owing to Wal-Mart’s size and the volume of products it orders, many vendors and manufacturers are adding RFID capabilities. Experts believe this will be the push RFID needs to become mainstream and as widely used as barcodes in product and materials management. Thirty years ago Wal-Mart began specifying barcodes on its packaging, bringing the technology into the mainstream.
Offices and remote locations can be connected to a wireless factory, but operations and data are primarily for use in manufacturing areas. One benefit of the technology, in fact, is improving the mobility of personnel by freeing them from their offices. “This is a very mobile business,” says Mike Puglia, director of product management for Bluesocket Inc., a Burlington, Mass., producer of WLAN management systems. “It gets people off the carpet and onto the concrete,” a reference to the technology’s ability to bring personnel out of their offices and into the factory. With new generations of handheld devices like PDAs configured to receive and send e-mail, enter and download data, scan barcodes, and even provide voice-over communications, advocates of the technology question whether offices are even necessary for employees of wireless factories.
When fully in place, wireless technology can dramatically improve a company’s operational efficiency and profitability. “If your inventory or shipping accuracy was 95% before wireless and increases to 100% after installation, you are going to save huge amounts of money,” says Shaun Deedy, strategic accounts manager for LXE Inc., Norcross, Ga., a developer of wireless hardware and software. Suppliers claim wireless improves manufacturing efficiency so much that many companies achieve a return on investment in 12 to 18 months. Little wonder, then, that manufacturing accounts for about 21% of the global wireless market, according to Puglia, and will post solid gains as the overall market doubles in size by 2008.
Wireless networks are straightforward in operation. Compact “gateway” receivers process signals from a company’s e-mail and factory-application servers and transmit them to access points in the factory. Access points, also compact wireless devices, transmit data to or from the factory floor. Personnel use access points to receive or transmit data throughout the factory with handheld devices. Using industrial PDAs, for example, employees can download information from a variety of sources, including their offices, view it on LCD screens with computer-like quality, and transmit it through the factory. Options like barcode scanners can be attached to PDAs and scanning data transmitted to colleagues in the factory or the front office.
Creating and maintaining the wireless networks require a dedicated technical staff. The most important consideration is making certain that access points and communication devices don’t interfere with each other. Suppliers and manufacturers generally don’t consider this to be a problem if care is taken in designing an installation. Stan Jenkins, who oversees spectrum management at Boeing Corp.’s Seattle factory, says users need to determine how much data will be traveling over bandwidths in areas around a factory, and then monitor and manage communications to prevent interference. Industrial wireless devices use the 2.4-gigahertz bandwidth, which has 11 channels, three of which, 1, 6, and 11, do not overlap. So, says LXE’s Deedy, it’s a process of laying out the communication cells in such a way that they don’t overlap or become overloaded.
Bandwidth capacity, however, is usually sufficient for plant needs. Five years ago, the Institute of Electrical and Electronics Engineers (IEEE) formalized a standard for wireless factory communications called 802.1 lb, which processes data at 11 megabits per second (mbps) in the 2.4-gHz bandwidth. To accommodate increased data demands from streaming media, video downloads (some robot-guided vehicles, for example, use digital imaging for guidance), and more users, the IEEE recently developed a related standard, 802.11g, which processes data at 54 mbps, yet is backward-compatible with devices configured for the 802.11b standard.
Security is a concern for wireless users, especially in urban areas or industrial parks where there is little open space between factories and, as Jenkins of Boeing notes, “coverage can go beyond where it’s intended.” Suppliers have software to preserve security. Internal wireless layout is also a factor. For highly confidential work, architectural and other features can be added to prevent signals from being transmitted beyond certain areas. Jenkins says some companies apply a microscopic metal coating to glass windows and partitions to limit attenuation without affecting vision.
When it comes to specifying a system, suppliers recommend that manufacturers first evaluate what they want to gain from wireless technology, develop a cost-benefit analysis, and then source equipment. Deedy advises that users steer clear of proprietary equipment and focus instead on hardware and software that conforms to IEEE standards. He also recommends that in sourcing handheld devices for use with a wireless network, manufacturers invest in quality products engineered for an industrial environment. “They’re not that much more expensive and will be a better buy over the long run,” he says. “Many companies wind up spending a lot of money trying to be cheap.”
Wireless technology is entering other manufacturing areas, such as sensors. Automation specialist ABB Group, Zurich, has developed a wireless sensor that powers factory robots. According to Christoffer Apneseth, program manager for global R&D at ABB’s office in Oslo, the sensors use a proprietary technology called WISA (wireless interface for sensors and activators) that draws on a magnetic field within the robotic cell. The system converts magnetic energy into electricity to power the robot and the sensors, which control movement.
Apneseth says the sensors eliminate the need for all the signaling cable that industrial robots utilize. This cable is the biggest reason for maintenance. Replacing it with wireless sensors will have a major effect on reducing lifecycle maintenance costs.
ABB is also developing wireless sensors for use in robotic tooling, which would be powered by transferring electricity from the robot to the tool.
COPYRIGHT 2005 Society of Plastics Engineers, Inc.
COPYRIGHT 2008 Gale, Cengage Learning