Delivering the right part to the right place at the right time is more than just a slogan at the Hopkinsville, Ky, plant where Grupo Antolin, one of the world's largest auto parts manufacturers, produces headliners for the Ford Explorer. It is a prerequisite to doing business with Ford.

Grupo must not only manage a product mix of 100 different styles of headliners - the interior cap on a vehicle's ceiling - it must also produce them in synch with the cars rolling down Ford's assembly line, a process known as in-line vehicle sequencing, or ILVS.

The ILVS process requires that the 2,000 unique headliners produced each day are delivered to the Ford assembly plant in the exact order as the trucks coming down the line. That way Ford's assembly workers don't need to think about which part goes on a vehicle; they simply reach for the next headliner on the rack.

'Ford demands near 100% accuracy, so we have almost no margin for error,' says David Cornelius, information systems manager at the Hopkinsville plant. 'With this system, we can provide the quality they expect.'

Making that happen requires several components. Taking the lead is a manufacturing execution system (MES) that utilizes bar codes, radio frequency identification (RFID), and pick-to-light storage bins (Connect, Inc., www.connectrf.com). Together they direct the processes and capture and share real-time production information across the supply chain.

Grupo's system combines several emerging manufacturing and Web-enabled supply chain best practices, including collaborative planning.

For those processes to work, accurate real-time information about Ford's production plans has to be shared across the supply chain, from Ford to Grupo to Grupo's suppliers.

'When you're looking at over 100 different styles of headliners made from a dozen different substrates, the possibility of an error is pretty high,' says Cornelius. 'There's no way we could meet Ford's expectations if we had to do this with a paper-based system.'

Because the system verifies parts for the operators, training is quick and easy, an important consideration in a setting where turnover can be high. 'The system will do a lot of the thinking for the operator,' explains Cornelius. 'That means we can train a new employee to be 100% proficient on any work station in a very short period of time.'

With greater control over the manufacturing process, Grupo improved the overall production rate, eliminating half a shift per day.

The system is highly responsive to shifts in Ford's production schedule. 'Ford has changed starting dates for us at least six times for various reasons, and each time we were ready to respond without disruption,' says Cornelius.

The process begins with demand forecasts sent from Ford through an Internet-based electronic data interchange (EDI) system. The files dictate the number of finished headliner units to be assembled and shipped in the near term and the next day.

First, an 8-week production schedule is updated weekly. Grupo extracts the bill of materials for the components Ford estimates it will need. Although the plan is subject to change, it allows Grupo to prepare for the next 60 days production. Since product is shipped just-in-time, Grupo's production schedule will very nearly mirror the automaker's production schedule.

The component requirements are then sent to Grupo's suppliers by phone, fax, and e-mail; an Internet-based system is in development.

A shorter term, operational plan is sent through EDI once a day. That file includes the parts Ford expects to receive in sequence over the next 8 days. Ford, however, is only committed to receive the next day's components, and reserves the right to modify the sequence after 24 hours.

Since inventory turns over nearly every day, the sequencing plan is also forwarded to Grupo's suppliers so they can plan their shipments for the next 24 hours.

'Storage space is key for us,' says Cornelius. 'We have a large facility here, but we're also producing a large product with a number of components. We can't afford to store more material than we need for the next day.'

The production schedule is downloaded to the sequencing operation, which begins to plan transportation for the shipments. The schedule is also sent to the molding operation where substrates - the bare headliners that will be customized and shipped to the Ford line - are produced. With the sequenced data, a scheduling program determines which headliner mold should be used for manufacturing the headliner substrate.

After a substrate is molded to size, holes are cut to accommodate dome lights, coat hooks, air conditioning ducts, and other features that will be added during the sequencing operation.

Once completed, the part is ejected from the mold and assigned a stock keeping unit (SKU) number and line ID information, including a time/date stamp. A bar code that tracks the part inside the plant is printed and applied to the substrate. The label is scanned and the substrate is stored on a rack in a work-in-process (WIP) area. The database of on-hand inventory is updated, and the part is ready to be sequenced.

While the substrates are in production, the sequencing process begins.

At the head of the sequencing line, an operator keys his location into a hand-held scanning device, then hits an option to get the next rack. That automatically prints the labels with the SKU bar codes for the next 11 finished headliners. The bar codes are printed in a predetermined sequential order that corresponds directly to the order in which vehicles are assembled at the factory.

The operator loads the substrates from the WIP area in sequential order onto a cart that is wheeled to the first work station where rear wire harnesses will be added.

A production worker loads the headliner onto an assembly table. A part sensor triggers a fixed-mount bar code reader. It scans the bar code on the sequence label, accessing the production schedule database.

Information about the part is sent to a robot that lays down a glue path for a wiring harness. That information is simultaneously passed to a pick-to-light storage bin, which identifies which harness to pick. The production worker has 20 seconds to install it before the glue dries. The pattern is then repeated for the front wiring harness.

Data about the components installed, the worker who installed them, and the time and date of the installation is captured as each step is performed in case of a product failure or a product recall, Cornelius explains.

When the work at that station is completed, the partially assembled headliner is handed in sequence to a production worker at the next workstation along the assembly line.

In all there are nine possible steps, depending on the components to be added from dome lights to air conditioning registers. At each station, the system scans a bar code to determine the appropriate assembly procedure for the robot, and the right pick-to-light bin for the operator. The same data collection and work-in-process tracking steps are also repeated.

Once those processes are complete, the headliners are placed on a conveyor and transported to the last workstation where visors and coat hooks are applied. The same scanning and data capture procedures are followed.

Because this is a time consuming step, there are three assembly tables at this station. Headliners are loaded according to the next available table, and can get out of sequence.

After the visors have been installed, headliners are inspected at a quality check station. Since they may be out of sequence, a series of red, yellow, and green lights above the visor tables alerts the operator at the quality check station which headliner should be inspected next in order to get the sequence right again.

If a part passes, it's loaded onto a shipping rack in sequence. At the front of the sequencing line, the process begins again on the next rack of parts.

Once all eleven headliners pass inspection, a shipping rack is ready to be loaded. Two bar code labels are printed with a rack identification number, a shipping destination, and high and low sequence number to identify the headliners on that rack.

A forklift operator transports the rack to the shipping area, and initiates the loading process using the vehicle-mounted terminal. The system identifies the next truck to be loaded and the next rack to go on that truck.

The driver then scans a label to verify the rack. The process is repeated until the truck is filled in sequence. Once all the racks are loaded, the operator closes the truck using the onboard computer. The systems prints the bill of lading for the transport driver, and the load leaves the dock for the assembly line.

Access to real-time inventory information is a must for keeping Ford's and Grupo's operations humming between shipments.

Within 15 minutes of a truck leaving the dock, the system sends Ford an advance shipment notification via EDI that tells Ford which truck is en route and what parts are on that shipment.

That same information is used to replenish the parts used to build the headliners just shipped. Workers servicing the assembly area carry a mobile computer. Each time a part is removed from the pick-to-light storage system, the inventory is automatically reduced by one in Grupo's enterprise resource planning system. When the inventory in the storage area reaches a pre-specified level, the worker is alerted and directed to a central storage area to replenish that part.

The driver scans the storage location, removes the parts, and then scans them into the pick-to-light system, updating the records.

Updated inventory levels are also shared with Grupo's vendors so that they can track the inventory on hand and manage their deliveries to the auto parts maker.

'In a real-time lean manufacturing facility, we don't have the luxury of storing thousands of wiring harnesses just in case we need them,' says David Cornelius. 'That means our inventory systems have to be incredibly accurate, and they are.'

Now that the system has proved itself in Kentucky, Grupo plans to expand it to other facilities, as well as other automakers besides Ford.

'In today's manufacturing environment, we have to be accurate and accountable,' says Cornelius. 'This system has given us the ability to sequence parts, reduce errors, and provide the kind of lot tracking that the automakers need for their records. It allows us to give them a better quality part, and that's good for both of us.'



Click here for more information about in-line vehicle sequencing systems.

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