The newest better idea at Ford
A new locating system determines where parts are in the factory, and delivers supplies on demand to assembly line stations.
By -- Modern Materials Handling, 6/1/2000
Jugglers have nothing over manufacturing production managers. While one tries to keep three or four balls in the air, the other has to coordinate the delivery of hundreds of parts to assembly lines in a timely and orderly manner without starving production or feeding it too much at any one time.
In a breakthrough approach to meet these challenges, Ford Motor Co. has turned to a real time locating system (RTLS) at some of its plants. This first-of-its-kind industrial information system (WhereNet, www.wherenet.com ) locates and tracks inventory using radio frequency identification (RFID) tags and a unique communications network. Antennas positioned throughout the factory receive tag transmissions, then deliver tracking information to a mainframe computer. The system then identifies the location of the tag within 10 feet of its exact position.
While the basic system is extremely helpful for inventory control, Ford has taken this new technology to another level. Instead of just placing the tags on inventory, Ford also places the tags at assembly stations. When a part supply is running low, a line worker simply presses a button on a tag that corresponds to the required part. The locating system then determines the tag issuing the call and dispatches a lift truck to retrieve the requested parts from storage and bring them to the line.
Since testing began on the system at Ford's Van Dyke plant in March of 1999, the system has been extremely accurate, with over 13-million transmissions without a missed communication. Materials are reliably brought to the line when needed, keeping the assembly line stocked for smooth operation. Labor efficiencies have been realized, flexibility increased, and an estimated $500,000 saved compared to a wired system.
"Our long-term expectation for the container tracking function is to drive down our inventories," says Mark Wrubel, project manager for Ford. "If you know where everything is, you should be able to have less of it."
On-line at Van Dyke
The nearly 2-million sq. ft. Van Dyke facility in Sterling Heights, Mich. produces over 9-million components annually for Ford cars and trucks. Chief among them is transmission systems for Taurus, Sable, and Lincoln models.
Since the locating system is still being phased in, remnants of the old tracking system are still being used.
Parts are received at Van Dyke according to a pre-set delivery schedule. While the plant has adopted lean manufacturing principles, most parts are placed in storage until needed at the line. When possible, parts are scheduled to arrive just in time for assembly.
A printed bar code label is applied to each incoming rack or container and then scanned into the warehouse management system (WMS), which determines the proper storage placement. While many Ford plants assign storage locations dynamically according to closest available, each part at Van Dyke has a permanent location where that type of part is always stored.
"Location X, for example is always used for Part Y," explains Wrubel. "When there is no part Y in the plant, Location X is empty. This is obviously a trade off-labor needed for this process is less, but our warehouse may not be optimally utilized."
When parts are required, the management system dispatches the driver with a printed assignment to that location. The driver pulls the part, rips off the paper bar code license plate applied in receiving, scans it, and then delivers the part to the line.
"The system relies on proper scanning of the item. If not, the WMS shows it is still in the warehouse," says Wrubel.
He adds that when a part cannot be properly located, someone has to go look for it, which involves additional labor costs. If it still cannot be found, then premium freight is required to bring in new materials quickly.
"You create a backwards snowball effect across the supply chain," he says. "It causes inefficiencies all the way through."
The new locating system tracks product throughout its time in the plant so there is little chance of losing it.
When a container is first received, a transmitting tag is attached. The tag identification is then married to the product ID of the item. Every four minutes, the tag transmits its location to continually update the WMS. The tags are designed so that they can stay with the container even after leaving the facility, as they have a battery life expectancy of 7 years. Right now, Van Dyke has 1,800 tags in its system.
Among the successful uses for the tag technology has been tracking racks of completed transmissions. Each rack holds ten transmissions, with the tag inserted into the dunnage dividers that separate the units. Most of the units are shipped to the Wayne, Mich. assembly plant, where another installed RTLS begins tracking as the racks reach the docks.
"We really wanted to test the location accuracy and robustness of the tag," says Wrubel, adding that the ability to transmit in a facility with a great deal of machinery operating was a good way of evaluating the technology. "We picked this metal transmission rack, a metal environment, a metal part that goes into the rack, and then the racks are all stacked upon one another, so it is definitely a harsh environment."
Currently, only the container number is written onto the tag. Ford will determine later what other information should be added to the tag and what will be placed into a database that ties to the tag.
For instance, history information is better served on the database where it can be accessed by anyone over the Internet. If the tag is lost, the part information is not.
Future data to be processed besides a rack's current location may include how many turns the rack takes; the quantity, part number, and description of parts currently in the rack; dates of rack usage; origin of the rack and destination; and whether the rack is full or is currently sitting available for new parts.
Bring it on
The call function has greatly enhanced the capabilities of the locating system. The application was developed jointly by WhereNet and the Ford subsidiary, Ford Global Technologies. The key to the system is the transmitting tag, now imbedded into a special housing designed for production line use.
The unit features a push button that initiates a transmission, a timer that begins counting once the call is sent, and a flashing light to confirm that the button has been pushed. It is easily mounted anywhere using Velcro fasteners.
"We told the line workers that 'You are the operators. You have to hit the button day in and day out. Put it where you want it,'" says Wrubel.
The flexibility of a wireless system became apparent immediately, as workers already have repositioned several of the 50 call tags at Van Dyke to line locations that are easier for them to reach. Such changes have no affect on assembly flow, far different from what would occur with repositioning a wired system.
Once an employee hits the call tag, the onboard light flashes ten times to confirm the transmission and the counter begins. The counter is a unique innovation that Wrubel added during the joint development to aid workers in identifying which tags have issued calls. For instance, assembly stations with multiple parts may have several call tags situated next to one another. The timers remind workers which tag they initiated and how long it has been since the call was made. This is especially important during change of shifts or team rotations.
The tag transmission is picked up by 16 antenna readers mounted from the plant ceiling. The readers pass the call information to the mainframe, which determines the location of the call tag and the part that is desired.
The system next triggers yellow lights to flash within the facility to notify lift truck operators that a pick up is required. A driver heads to a central assignment station and pulls the truck up to an eye-level touch-screen monitor. The touch screen allows the driver to interact with the system without leaving the cab, displaying information such as part location and where it needs to be delivered.
As the driver touches the screen to confirm the assignment, a pick ticket is printed next to the monitor. The driver is then able to take a printed record along to the storage area.
The drivers learned the technology quickly and are now familiar with the storage and line locations, so they now spend little time interacting with the display screens. They merely stop quickly at the terminal and pull several pick assignments at once.
"They love it now," says Wrubel.
Before installing the new call system, Van Dyke's workers had delivered the amount of material to the line that was necessary to complete that day or shift cycle. Needless to say, that was a lot of extra material lying around.
"Going to a call system was a learning curve for us," says Wrubel. "We were a push system, now we are a pull system."
Wrubel couldn't be more pleased with how Ford workers have adapted to the new system. "The line side operators love it for the flexibility," he says.
Wrubel also says that Ford has just recently given full corporate backing of the technology for use in plants worldwide.
"It has the accuracy we want, he adds. "We have seen it fully meet our expectations." the Van Dyke plant.
Accurately tracks materials in facility
Brings parts to the line as needed
Utilizes labor more efficiently
Cost savings over hard-wired systems
Faster installation permits facility to be online with call system in one month
Wireless system allows for flexible line adjustments
Proven reliability with over 13-million calls and no misses
Ford Motor Company
Van Dyke Transmission Plant
Sterling Heights, Mich.
Facility facts:
Facility size: 1,960,371 sq. ft.
Number of units produced in 1998: 9,115,855
Employees: 1,574
Products: Transmissions, transaxles, suspensions, CV joints, halfshafts, arms, spindles, knuckles
Equipment suppliers:
Wireless locating system: WhereNet 408-845-8500, www.wherenet.com
Lift trucks:
Hyster 252-931-4978, www.hysterusa.com
The Raymond Corp. 800-235-7200, www.raymondcorp.com
Clark Material Handling 606-288-1200, www.clarkmhc.com
Assembly conveyor and automation systems:
ABB, 262-785-3400, www.abb.com
Transmission shipping racks:
Yukon Manufacturing, 877-299-8566, www.yukonmfg.com
Transmission rack dunnage:
Creative Techniques, 800-473-0284, www.creativetechniques.com
From the time that Henry Ford revolutionized manufacturing with the assembly line, Ford Motor Company has always been on the cutting edge of new technologies. The company spends more than $6-billion each year on research and development, and has amassed a staggering 5,000-plus patents.
"Ford has a huge intellectual portfolio. We have a lot of inventors here," says Ford spokesperson Maria Sheler-Edwards. She says that some of those innovations comes from cooperative efforts, such as the WhereNet call tag project.
Ford Global Technologies, Inc., a wholly-owned subsidiary of Ford created in 1997, recently entered another supply chain joint-development venture beyond its agreement with WhereNet.
That partnership with SynQuest resulted in an inbound logistics software. The application is being deployed by Ford to reduce logistics costs while increasing the frequency of shipping. SynQuest is marketing the software to others, including Ford suppliers.
The development partnerships help Ford to reduce operational costs through use of the technologies produced, and also provide an additional revenue stream to Ford shareholders. Ford also donates technologies to universities and non-profit institutions, such as the University of Michigan. Most of these intellectual properties are given in the hope that additional research will yield new applications apart from those used by Ford and its subsidiaries.
"Ford is transforming itself into a consumer-based company. Part of that involves leveraging our intellectual property assets to derive the most value we can for our shareholders and consumers," says Sheler-Edwards.
Developing the call system application has helped Ford engineers to gain the benefits of the container locating system with little additional investment. That is because the systems share the same transmitting and receiving infrastructure. As more applications are added, the costs come down and the savings increase dramatically.
For example, one Ford plant is using the locating system for garbage collection. Call tags similar to those used at Van Dyke are placed on dumpsters. Once the dumpster is full, an employee presses the call button and a truck is dispatched to pick up the load. Before installation, trucks circled continuously searching for dumpsters that needed to be emptied.
Ford may further extend the technology to track hazardous materials within its facilities.
The tags may also be used to stage materials used by engineers for new designs. Each tag can be identified with a particular project to make locating parts for that model much easier.
Tags may also be attached to finished cars as they come off the assembly lines, so that they can be easily located in the storage yards.
Similarly, the system can improve yard management of Ford's supply trucks. The time is coming when individual bar codes will no longer need to be scanned. Instead, the contents of a truck can be determined simply by reading the locations of the items. The system is able to immediately audit the load and update the databases. Tying the databases to Internet access provides even greater management potential.
"With the Internet and the wired world today, conceivably a manager could be driving down the freeway in a car with Internet access and take a look at inventory in plants around the world," says Tom Bacon, director of industrial relations for WhereNet.
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