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Carlisle Tire & Wheel takes its upgraded DC out for a spin

The following is from an article published in February 2002 Modern Materials Handling Magazine.

Productivity increased 20-fold following implementation of a new WMS, sorter, and paperless systems. They are practically leaving skid marks now.

Have you ever scrounged around your garage trying to remember where you placed those winter treads for the car? Imagine what it would be like to face the problem of lost tires everyday. That is exactly the situation at Carlisle Tire & Wheel. This manufacturer of industrial tire products had a serious problem of controlling inventory until it recently upgraded its distribution center with impressive results.

"We came from a 250,000 square foot facility with no locator system to where now we have an effective management system," says Dick Hock, material distribution manager. "Where some places have FIFO - first in first out, we had FIST - first in still there."

Hock says that countless hours were spent looking for inventory under the old systems. Today, items can be found quickly, thanks to a versatile warehouse management system (RT Systems, www.rt-systems.com). Coupled with a wireless order processing, new sorting system, conveyors, an efficiently designed picking mezzanine, and new packing areas, Carlisle increased its productivity by 20 times its previous levels.

"Before the upgrades, we picked less than one-half a tire per man-minute. Now it is 10 tires per man-minute," says Hock. " We came from the stone age of warehousing and distribution into the rocket age." Accuracy has also jumped dramatically. Prior to the new systems, the company experienced shipping errors costing up to $10,000 monthly.

"Our recent internal audits show 100% accuracy," says Sam Stover, distribution manager. "We also went from a three week backlog to being capable of a same day shipping schedule." Founded in 1917, Carlisle Tire & Wheel produces tires for lawn and garden equipment, golf carts, and trailers. The company's tires range in size from 4 to 16 inches with some 25,000 manufactured daily at a local plant in Carlisle not far from the distribution center. Wheels and other products are also produced at plants in South Carolina and California.

Customers include OEMs of mowers, golf carts, and trailers such as Sears, Cub Cadet, Yamaha, and EZ-Go. Large retailers such as Wal-Mart, Pep Boys, and Discount Tire also sell replacement tires. This is the busiest time of the year for the distribution center, as it is during the early part of the year that retailers prepare for the warm outdoor season ahead. Some 65,000 tires ship daily from the Carlisle DC during its peak season. This facility, built originally in 1987, is now the most efficient it has ever been. "We have gone from a 7-day, 4-shift schedule to where we are now 5 days and 3 shifts," says Hock. "We hope eventually we can cut back to two shifts and use the third for replenishment."

Making tracks
Tires are produced just a few miles away and hauled to the distribution center where upon arrival the trucks pull up to the facility's 10 receiving docks. Dock levelers adjust to allow lift trucks to easily enter the trailers.

Most tires are received in either gaylord corrugated containers on pallets or wire racks with plastic tops and bottoms. The racks are affectionately known as "dog cages" at Carlisle Tire & Wheel. An average of 900 pallets or container racks are received daily. Each has a bar code that was attached at the manufacturing facility which a lift truck driver scans upon pick-up. Instantly, his scanner/radio frequency (RF) device displays the appointed storage location.

The majority of receipts, with the exception of items needed for immediate replenishment, head directly to reserve storage in a building addition constructed five years ago. Almost all is stored at floor level, with the exception of tire tubes, which are stored in a small amount of pushback pallet racking. Upon arrival at the designated storage location, the lift truck operator scans a location bar code into the RF device. Signs hanging from the ceiling contain the bar code for floor level locations, while the pushback racks have bar code labels attached to them. The driver can also input the storage location by hand if desired. Both methods confirm proper putaway.

If a received item is needed right away in a forward pick area, the lift driver will be informed through his RF unit of where to take the receipt. Also, a small amount of receipts needing a correction in packaging or labeling is diverted to a re-pack station before taken to storage.

Stock keeping units (SKUs) are defined at Carlisle as A-D, with A representing the fastest movers and D the slowest. All A and most B items are placed into the back of the new three-level pick module that features pushback pallet racks. The remaining B, C, and D SKUs are placed on the floor in designated picking zones. Floor racks also hold some of the tires for picking.

Replenishment takes place continuously throughout the day, with the vast majority pulled from reserve storage. These are brought by reach or lift trucks to the rear of the pick modules or the floor-level picking areas. Counting all space in reserve and the modules, the facility contains a total of 2,300 storage locations.

Kicking out the tires
Orders are first processed at Carlisle Tire & Wheel's facility in South Carolina. Data is then transmitted to the WMS at the Pennsylvania distribution center for fulfillment. The day's work is based on customer-requested shipping dates, though the facility now has the ability to process same-day shipments if desired.

The WMS creates waves from the orders, grouping together like SKUs. Carlisle runs about 15 waves each day. The WMS next directs the printing of batch and product labels. Each stack of labels contains a header label describing the wave and batch, a task label explaining to the picker which SKUs to select and where they are found, and bar code labels that are placed on each tire as it is picked.

Hock says that moving to the new paperless system has made picking easier, resulting in greater accuracy and productivity in the picking areas. "In our peak seasons, about 50% of our workforce is temporary," he explains. "We wanted to get away from paper and have a system that is easy for them to use."

Most picking is performed in the module. Workers first scan the task label on each batch with their RF scanners. The device displays SKUs, quantities, and locations to pick. Once arriving at the location, the worker scans a location bar code and begins picking the required tires. Each is given a label, placed on the sidewall of the tire, as it is deposited onto a take-away belt that winds through all three levels of the module. If a particular SKU is getting low within the module, the operator can key in a replenishment request directly from his RF device. Picks continue until all selections in the wave have been completed.

Similarly, picks of slower-moving products are pulled from the wire racks and other floor locations in B, C, and D areas. These are placed onto carts. Again, task labels are scanned along with locations, and labels are attached to each product as it is chosen. The carts are then taken to a bulk induction station, where each tire is placed onto a belt. The induction station is actually the beginning point of the same conveyor that snakes through the module.

Orders that require a full pallet of tires may be picked directly from reserve storage and taken directly to shipping where they are staged. In this case, the pallet is scanned by the lift operator upon pick-up and labeled before being taken to the docks.

Often, however, customers require compliant labeling of their purchased tires. In this case, labels are printed and the load is taken to the bulk induction area instead of directly to the dock. Each item is pulled from the pallet, labeled, and placed onto the induction belt. Similarly, cartons containing tire tubes are pulled from the pushback racks in reserve storage. These are also brought to bulk induction for labeling and processing.

After feeding through the module, the belt carries all tire picks and cartons to the facility's pop-up sorter. The sorter contains 30 diverts arrayed on both sides. One serves items shipped by parcel post, another is a jackpot lane for unreadable items or those requiring special processing, and the remaining 28 serve packing lanes.

Upon entry to the sorter, a fixed scanner mounted over the belt reads the bar code of the label that was applied when the tire or carton was picked. This information tells the sorter onto which lane to divert the item. As it approaches the correct lane, rollers pop up from the conveying surface and redirect the tire or carton down the gravity-fed spur that will gather that order.

Packers at the bottom of the lane place each item into a carton or a gaylord box depending on size of the tire and quantity of the order. Larger tires may also be stacked onto a pallet.

Once all items for an order have been diverted, a green light illuminates to signal to a lift truck driver that the load is ready to be taken to the staging area by the docks. The driver gathers the load and if necessary, takes it to a stretch wrap station before taking it to staging.

At staging, all outbound cartons are accumulated and then loaded by lift truck or pallet jack onto over-the-road trailers parked at the nine shipping docks. Most tires today ship directly to a customer's store, which is a change seen in recent years.

"We went from shipping a lot of 2,500 lb. pallets to customer distribution centers to now where we have mostly 350 lb. cartons shipments," says Hock. "For instance, we ship anywhere from 200-500 shipments a day directly to Wal-Mart stores."

Additionally, some tires are transported to the South Carolina and California facilities for special processing, such as tire mounting.

Shifting into gear
Impressive as the change has been, Carlisle Tire & Wheel is just now beginning to see the results of its upgrade. "The success story we have had has only been in about 6 months," says Stover. "We have been quite pleased so far," adds Hock. "We still have a long way to go in tweaking this system, but we are way ahead of where we were a year ago."

After many years of doing work at a much slower pace, the employees have also adapted well to the system. "They are pleased with the changes," Hock says. "They would much rather pick something quickly than spend 20 minutes looking for it."

Hock adds that Carlisle Tire & Wheel has achieved its objectives of increasing productivity and it shipping accuracy. Because of the efficiencies gained, he expects to see a return-on-investment in only 16 months.

Modeling the DC
When Carlisle Tire & Wheel created its facility, it used modeling software provided by its integrator (Fortna, www.fortna.com) to help determine ideal materials handling designs. Information about the previous year's order activity was entered into the software along with SKU information, such as individual product weights, dimensions, packing needs, and special handling requirements. The software was then able to identify that a relatively small number of SKUs were typically needed to fill most orders.

"A pick module suited these SKUs well," recalls Phil Godden, vice president of process improvement for Fortna. "We ran about 25 models for Carlisle until we found out how to best serve their needs." The models helped to determine velocities, the ideal slotting of SKUs, potential bottlenecks, and the proper balance between the items in the pick module and those in reserve storage.

• Carlisle Tire & Wheel Co., Carlisle, Pa.
• Facility size: 250,000 square feet
• Throughput: 65,000 tires per day peak
• SKU's: 1,200
• Employees: 90

• Greatly improved inventory tracking
• Moved to paperless processing
• Eliminated one shift, reduced headcount
• Accuracy improved significantly
• Same day processing capability