Aug 26, 2013Whirlpool Corp. is the world's leading manufacturer and marketer of major home appliances. Its Clyde Division, based in Clyde, Ohio, is the largest washing machine facility worldwide, covering roughly 2.5 million square feet. Maintaining a highly accurate parts count is necessary to ensure the constant availability of parts for production, says Bradford W. St. Louis, the company's senior materials engineer.
The input to the paint line is raw stamped parts, while the output is ready-to-assemble washing machine components. Accurate parts tracking also affects finished product quality, St. Louis says. "We paint our cabinets in a different area from our tops and lids, so we have to make sure we have everything matching," he explains.
Yet, until recently, employees could only identify the racks of raw stamped metal tops and lids in production by reading the information printed on attached paper tags. That process was both paper-intensive and error-prone, St. Louis says.
Last year, the company decided to replace its paper tag-based parts-identification system with a more efficient RFID solution. "Whirlpool puts cutting-edge technologies to use in areas where they promise to be the most effective," St. Louis states.
Whirlpool's washing machine paint line is continuously fed with parts that are transported to the area aboard tagged mobile racks. "On our old system, workers would hang the parts on paint hooks," St. Louis recalls. "The parts would then go onto the line and come out painted." Workers would next take the painted parts and place them onto a rack, with a white paper tag with a part number on it identifying each part. "They would hang the tag with a metal hook that looks like a bent paper clip," he says. "Then a fork truck driver would be able to identify the parts that were on that rack." As the painted parts headed toward storage, a paint line worker would also manually enter the information into an electronic journal.
The process was inelegant. "The tags sometimes fell off, or the racks were inadvertently placed behind other racks with a different part number because we're very limited on space here," he explains. "Even though we're a 2.5 million-square-foot facility, we have limited room to spare."
The old system was also prone to creating production interruptions. "We would misplace parts," St. Louis says. To keep production moving, management would then order a production schedule change. "When we couldn't find the parts that we needed to run production, everyone would scramble to try and slide another model into production that we knew we had the parts for. It had to be done, because we cannot lose production time."
With the new system in place, an RFID tag is attached to the top of each rack and a display to the front, so paint-line workers can easily identify an arriving rack, thereby ensuring that the correct powder coating color is applied to each component. The technology also serves another purpose, St. Louis notes: identifying and recording parts as they are either added to or removed from the racks, enabling management to maintain a live, accurate count of all parts being used on the paint line. "Previously, we would audit part counts every morning, noon and night," he states.
What's more, the solution helps to protect the environment. Eliminating the little paper tags used for parts identification on a washing machine manufacturer's paint line may not seem like a big deal, St. Louis says, yet Whirlpool is committed to cutting waste wherever it can be found. "The changeover to RFID will not only eliminate the paper used to identify and record parts production quantities, but also the paperwork needed to take periodic audits," he says. "This allows a significant saving of both materials and time."
Planning a New Approach
Seeking a faster, more accurate method of identifying components, Whirlpool's improvement teams began thinking about adopting a bar-code solution. "They considered putting bar-code labels on every rack at a cost of 4.5 cents per label," St. Louis says. "That would mean going through hundreds of labels a day."
Management was focused on a bar-code-oriented solution when St. Louis proposed another idea. "For a little bit more money up front, we could use RFID and have zero operating costs," he suggested. "In addition, we'll need a lot less labor and will have higher accuracy than with a bar-code solution."
A cross-functional team began planning an RFID solution that would eventually replace the existing paper tag system. After surveying the market, the team identified Omni-ID as the company best prepared to develop a solution to meet Whirlpool's targets. "We closely collaborated with Omni-ID over many months to install, test and then validate a system that would eliminate the use of hanging paper tags at the paint line," St. Louis says.
After examining Whirlpool's paint line infrastructure and goals, Omni-ID recommended an ultrahigh-frequency system using Omni-ID Max tags and Impinj R420 readers linked to Laird Technologies compact 4x4 antennas. To update the displays, Omni-ID specified its 3-inch View tag and its ProView gateway. The readers and gateways are installed in the ceiling, with antennas extending over the rack fill placement location. Omni-ID also provided the software that allows users to view a real-time count of parts currently in use. "This was unique to our business and developed by Omni-ID," St. Louis says.
As a rack is moved into position for loading, its tag is read and the unit is identified. When the rack is completely filled with painted parts, the work-in-process inventory is automatically updated to show the added items. At the assembly line, another reader identifies the rack. Once all parts have been removed from the unit, an "Empty" message is sent to the display and the work-in-process inventory is once again updated, allowing for real-time inventory management.
Testing and Deployment
Prior to deploying the technology at the Clyde facility, Omni-ID tested all relevant use cases at its Rochester facility. After the tests were concluded, the firm compiled a final report incorporating performance results and installation instructions. "We then had planning meetings to discuss the installation requirements," St. Louis says. A trial was focused on the paint line using a small subset of parts. Expansion to additional painted components would be a simple matter of adding more RFID tags and displays to the component racks, he explains.
According to St. Louis, the testing revealed no major surprises. "There were no read rate issues," he says. "Connecting the hardware was the biggest challenge."
As the solution was taken live, staff members were trained on the technology and how it would impact workflows and inventory management. Training was minimal, however. "We were careful to ensure that the systems fit into the existing workflows," St. Louis states, "so little change was implemented into the normal operations."
The project took almost nine months to complete, primarily because hardware installation had to be limited to weekends, to prevent any disruption to production. "We've been online for three or four months now," St. Louis says. "We're actually still parallel pathing—using both RFID and the paper tags—but we're getting extremely close to relying on RFID to maintain our inventory."
The system is meeting its designers' expectations in every way, St. Louis reports. "We're now able to view accurate real-time work-in-process inventory, allowing for leaner management of assembly and delivery operations," he says. Whirlpool is already looking ahead to the system's next stage. "Moving forward, we plan to integrate the RFID solution into the company's SAP-based enterprise resource planning software." The move is expected to open the door to even deeper and more accurate parts supply and demand analyses, he adds.
According to St. Louis, Whirlpool is so pleased by the system's performance that it is now looking into other ways of using RFID to cut waste and improve efficiency and organization. "We are talking with Omni-ID about several additional uses of the technology," he says.
One possible project would employ RFID to help manage the timing of assembly component deliveries. "Our facility produces a tremendous number of units daily and requires careful planning for the delivery of goods to assembly," St. Louis states. "Managing those deliveries is like being an air-traffic controller without a radar screen."
By using RFID to time deliveries, avoid traffic congestion and keep dock operations flowing smoothly, Whirlpool hopes to bring a high degree of order and organization to what can be an occasionally chaotic process. "We are investigating the feasibility of using RFID to help manage timing by creating real-time feedback to material drivers as to whether they are ahead or behind schedule," St. Louis says.
St. Louis believes that RFID is destined to eventually play major roles throughout Whirlpool's manufacturing and supply chain processes. "Our current system has served us for many years," he concludes, "but the added capabilities of real-time inventory tracking will help us meet customer demands more effectively and efficiently, at a lower cost."