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High-Tech Delivery PUBLIC ACCESS

The U.S. Postal Service is Automating its Vast Infrastructure to Stand up to its Competition.

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Associate Editor

Mechanical Engineering 126(08), 38-42 (Aug 01, 2004) (5 pages) doi:10.1115/1.2004-AUG-4

The US Postal Service is automating its vast infrastructure to stand up to its competition. The Postal Service is betting that investments in modern technology can help it improve efficiency and reduce costs. The tactic is part of an overall strategy, known as the Transformation Plan, to keep the Postal Service competitive in the face of competition from e-mail and private carriers, an expanding network of delivery points, and declining revenues. Wide Field of View cameras boost productivity of letter-sorting machines by reading a higher percentage of barcoded mail. The 534 Advanced Flat Sorter Machines, deployed in 2001, use optical character recognition and remote keying technology to sort mail into 120 separations. The Postal Service is integrating systems within processing facilities as tubs and trays are combined into larger wheeled containers for shipment. The Postal Service has established the Mail Technology Strategy Council to help it evaluate innovative technologies. The council consults with industry to get an idea of where modern technologies are headed and which ones are feasible to incorporate.

The United States Postal Service has a reputation for going the distance to deliver the mail. Postal workers have braved feisty dogs and bitter cold. They have lugged the goods up mountain slopes and faithfully covered rural routes on battered rustic roads and sometimes on no roads at all.

Today, with so much of the country connected by efficient paved highways, those routes are few and far between. These days, the big challenge for the service is to keep up with the volume.

The Postal Service is betting that investments in new technology can help it improve efficiency and reduce costs. The tactic is part of an overall strategy, known as the Transformation Plan, to keep the Postal Service competitive in the face of competition from e-mail and private carriers, an expanding network of delivery points, and declining revenues. Engineers—particularly mechanical engineers—are playing a key role in the Postal Service's efforts to streamline its organization.

Tom Day, vice president of engineering for the Postal Service in Merrifield, Va., describes four areas of investment for distribution technology: letters; flats, which are oversize mail pieces such as catalogs and magazines; packages; and overarching mail handling technology. Automating mail handling poses two basic challenges, he said: One is physical transport of the mail piece to the appropriate bin; the other is being able to read the address in order to identify the destination.

New investments from now until the end of the decade will focus on two initiatives. One is more robust material handling to move mail throughout the system: automating how containers are moved from the sorting machines through the plant and how pieces are combined and loaded into trucks. The other is at the end of the distribution network where mail is delivered to households and businesses. Those efforts are part of a comprehensive automation plan that has encompassed sorting letters, flats , and packages—three broad categories of mail—over the last 15 years.

The Postal Service has been trying to hold down its labor costs, and Day said that automation could also reduce accident and repetitive injury rates as well as improve accuracy. The Postal Service has reduced the number of career employees from roughly 776,000 in 2001 to 720,000 today.

Letters, flats , and packages that enter a postal facility have to be sorted and sent on their way fast. Of the three, packages represent the most difficult technical challenge, because they come in a range of sizes and shapes, and are the most recent of the three product stream5 to be automated. The Automated Package Processing System, or APPS, is supplied by Lockheed Martin. The system handles a range of package weights and sizes, from one-tenth of one pound to 25 pounds and sizes from 0.05 × 3 × 3.5 inches to 15 × 18 × 22 inches, according to Judy Marks, president of Lockheed Martin Distribution Technologies in Oswego, N.Y., which built the system.

The APPS system, which is over 300 feet long, consists of a series of belts, cameras, and output chutes. A heterogeneous stream of parcels enters the system. Packages travel along conveyors, through a series of inclines and declines that put the packages into a single file.

The single line of mixed packages passes through an identification system, where each parcel is weighed and measured, and the address is identified. The system includes optical character recognition systems and barcode readers. Software locates the address on anyone of six sides as packages advance at a rate of 9,500 per hour. Packages are sorted to anyone of 200 output chutes, according to destination. Lockheed Martin installed the first system at the Twin Cities Metro Hub in Minneapolis in January, where it has completed testing. The company will supply a total of 74 APPS systems to the Postal Service.

Postal workers in rural Michigan delivered parcels and other mail on horseback in the early 20th century. The photo (opposite) was taken sometime in the early 1920s or '30s.

Before automation, postal employees sorted mail manually into separations based on the destination city. The average case had 49 separations.

Grahic Jump LocationBefore automation, postal employees sorted mail manually into separations based on the destination city. The average case had 49 separations.

The Postal Service took about a dozen years to automate the sorting of letters, and roughly half that to automate flats, Day said. Automated letter sorting, accomplished in the early 1990s, is based on pitch-belt technology, and sorts at a rate of about 35,000 pieces an hour. Flats, a mix of magazines, catalogs, and oversize mail weighing up to 20 ounces, cannot be handled as quickly. A carousel setup of carts transports the pieces and drops them in appropriate bins.

Day said the Postal Service was working on a more robust material handling system that integrates key components as the mail is sorted, and moved in tubs and trays on belt conveyors and powered roller conveyors around the facility. Ultimately, the trays and tubs have to be emptied into larger containers, rolled onto trucks, and sent to upstream and downstream facilities.

Day's goal is to take the human element out of material handling as much as possible, with the aim of lowering labor costs, boosting accuracy, and improving safety and reducing injuries. Continually transferring the contents of trays and tubs into larger containers entails lifting, bending, turning, and twisting that result in soft-tissue and repetitive-motion injuries. "A letter tray might weigh 20 to 25 pounds; a flat tub might weigh 30 to 35 pounds," he said.

The human factor has not quite been eliminated from sorting tasks. Day estimates that five to six percent of the total mail volume is still sorted manually.

Marks said that better material handling systems that focus on continuous flow in the receipt, processing, and dispatch of products could help avoid ergonomic problems and lower-back injuries. Part of the Postal Service's plan to automate its dispatch operations is the installation of an Automatic Flats Tray Lidder system. The AFTL system automatically places lids on containers of flats before they are transported from one of 400 processing centers to facilities for final delivery. The containers need to be closed and moved without getting the contents out of sorted sequence. Replacing a manual process, the system automatically uses a high-speed motor and vision system to place and secure lids on the containers before shipment. Lockheed is under contract to supply 120 systems to the Postal Service.

Day said the Postal Service is integrating systems within processing facilities as tubs and trays are combined into larger wheeled containers for shipment.

Wide Field of View cameras boost productivity of letter-sorting machines by reading a higher percentage of barcoded mail (top). The 534 Advanced Flat Sorter Machines (bottom), deployed in 2001, use optical character recognition and remote keying technology to sort mail into 120 separations.

Grahic Jump LocationWide Field of View cameras boost productivity of letter-sorting machines by reading a higher percentage of barcoded mail (top). The 534 Advanced Flat Sorter Machines (bottom), deployed in 2001, use optical character recognition and remote keying technology to sort mail into 120 separations.

Day refers to the delivery of letters and flats to households and businesses as an " untapped frontier." Mail carriers typically handle 500 to 600 residences a day. Before delivering the pieces, they must sequence them in the order of the route. It's a lab or-intensive practice that can take two hours. Day hopes the Postal Service will have equipment in place by the end of the decade that will package the mail for the carrier each morning.

To date, the Postal Service has done some sequencing of letters, but not flats, Day said. The Service has funded an R&D effort with its major suppliers, which are working on concepts and simulations. "We have seen some interesting approaches on how you would merge all this mail together," Day said. He declined to give specifics, but said one of the critical issues is how the mail would be packaged and transported to the mail carrier.

Lockheed Martin is one of the companies working on flats sequencing. One question, said Marks, is whether to sequence letters and flats separately and require the carrier to handle two bundles, or to do the final sort combining the two product types into a single bundle. Lockheed Martin and one other competitor are working on flats sequencing. The company and four of its competitors are working on a delivery point packaging scheme that would provide pre-sequenced letters and flats in one package for delivery, Marks said.

Lockheed Martin's approach is to add a material handling conveyance system to an existing flats sorter for a second sort that gets to the route.

The Automated Package Processing System that is currently being deployed can process more than 9,500 packages per hour of first-class mail, which is discharged via mail chutes into the appropriate containers (inset).

Grahic Jump LocationThe Automated Package Processing System that is currently being deployed can process more than 9,500 packages per hour of first-class mail, which is discharged via mail chutes into the appropriate containers (inset).

Standardization goes hand in hand with modernization, as obsolete equipment is replaced. "We are trying to limit the equipment set that we use," Day said. "It forces standardization. If every facility has the same equipment with the same number of output bins, you could use standardized sorting programs that are very uniform."

Using the same basic set of components in machines helps keep upkeep costs in line and allows bulk-quantity purchases. Standardization could help trim training costs at the large maintenance facility in Norman, Okla., where ~h e Postal Service has set a goal of training technicians to l11.aintain the same equipment no matter where it is located in the country. To that end, it is replacing its older equipment at the facility with the smaller, newer equipment.

For facilities built in the last 20 years, the Postal Service has attempted to stick to six basic layouts: small, medium, and large facilities with one or two floors. The standardized footprint, to the extent it's possible, could help to standardize layouts of the equipment and processes in the facilities.

Standardizing the layouts of older facilities may be a tougher problem. The Postal Service has 283 distribution facilities, excluding ones that serve as hubs for air transport. Mail is brought in, sorted, and sent to other facilities in the network. Those distribution facilities vary greatly. Some of them were built in the 1930s under the federal Works Projects Administration. Other facilities, particularly in urban settings, can be several stories high.

The Postal Service has established the Mail Technology Strategy Council to help it evaluate new technologies. The council consults with industry to get an idea of where new technologies are headed and which ones are feasible to incorporate. "It's trying to look into the future and understand where technologies are going," said Day, who participates in the group.

Barcode labels akin to license plates would be applied to mail pieces so they could be tracked as they travel through the postal network, providing unique identification without human involvement.

One focus of the group has been intelligent mail. The Postal Service currently uses a number of different barcode formats. One effort is directed at consolidating all of its information needs into one barcode. The strategy council has examined two-dimensional barcodes, which can store greater amounts of data than traditional linear barcodes now in use. That may be premature, though, because high-speed printing of two-dimensional barcodes is still several years off. That would keep the technology out of reach of high volume customers, such as credit card companies and financial service firms, Day said.

Northrop Grunmman Corp. in Los Angeles is working on a barcode system used to track mail pieces. Barcoded labels, akin to license plates, would be applied to the piece so it could be tracked wherever it goes throughout the postal network, without human involvement, according to Gabe DiFurio, Northrop's director of postal automation. While barcodes are used extensively in the postal system, this would be the first time they have been used to do unique identification of mail pieces, he said. He added that the Postal Service has settled on an international standard for the barcode, so it could be read in other countries as well.

Day' said that optical recognition technology is the backbone that has made automation of mail distribution possible. He said that optical character recognition equipment could process addresses—name, street, town, state, and ZIP code—and match them against a national database to determine the extended ZIP code, in 300 nanoseconds. He said the Postal Service has largely eliminated the human factor in sorting and distribution tasks.

In September of last year, the Postal Service completed upgrading approximately 10,000 cameras that are used on automated letter-sorting machines. The new Wide Field of View cameras, supplied by Lockheed Martin, can read the whole face of the envelope, which can be up to 6.25 inches in height. The old wide area barcode readers could read only a 4-inch band, leaving a 2-inch gap. The new cameras use light-emitting diodes, which generate less heat and are safer to handle than the older barcode readers, which used halogen lights, according to the Postal Service.

Transporting mail could also be in line for an upgrade. Much of the mail that is shipped around the country—particularly that moving more than 50 mile—is carried under contract by outside suppliers. At either end of the network, where mail is received and where it is delivered to the handler, the Postal Service uses its own fleet of trucks.

Letter carriers carry handheld scanners to track product deliveries. The barcode device currently in use is reaching the end of its life cycle, and the Postal Service is investigating a replacement. One possibility, said Day, is a device equipped with a global positioning system as well as wireless conductivity capabilities.

"We are looking at it a couple of ways, and we have not made a final decision," he said. There are several possibilities, including embedding the handheld device with GPS capability as well as wireless communications capability. Yet questions remain. For one, wireless access is still limited in many rural areas.

But there's a consolation. Although wireless relay towers may not be handy, at least most of those rural areas have paved roads now.

Automated Package Processing System (above) transfers bundled magazines from pallet to conveyor, where they'll be put into single file and sorted upstream. Postal Service is installing 74 APPS systems to replace previous-generation small parcel and bundle sorters (top).

Grahic Jump LocationAutomated Package Processing System (above) transfers bundled magazines from pallet to conveyor, where they'll be put into single file and sorted upstream. Postal Service is installing 74 APPS systems to replace previous-generation small parcel and bundle sorters (top).

Copyright © 2004 by ASME
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