Inline-vehicle sequencing lets manufacturers make better use of plant floor space because it organizes parts and components in the order they will be assembled on the line and delivers them to the line within a few hours of being needed.
"Everybody is trying to get more into these facilities with less space," says Madison Hts., Mich.-based Andy Saladin, a senior project manager for Orbis Corp. (Oconomowoc, Wis.). " Sequencing and the packaging help to facilitate that. You can have more [packaging] options without taking up more space. That is the huge benefit of the kitting and sequencing. You now have a wide variety of options, but the floor space that goes along with it in your manufacturing facility is not any more."
Today, automakers manufacture vehicles for the global market. One line can produce several car models for different countries, including right-and left-sidedrive vehicles. Just imagine the floor space that would be needed to store six colors of rearview mirrors for each of two different car models being built for several countries. Sequencing eliminates such inventory storage, allowing for better assembly line space utilization, and produces greater assembly accuracy, lower costs and less overall time required to build vehicles.
Producers of material handling products are supporting inline-vehicle sequencing with new systems that make picking faster and more accurate and ergonomically designed containers that have smaller footprints and are safer for operators to use. A new pick-to-build system, for example, lets operators quickly and accurately put together components. New reusable containers and racks are doing a better job of protecting products and reducing the number of damaged parts. The new ergonomic designs of containers and racks reduce worker injuries. Finally, automatic-guided vehicles (AGVs) and carts are delivering parts and components to assembly lines more safely and efficiently. Here is a roundup of some of the systems and products being used to make automotive sequencing possible and effective.
Picking Parts Accurately
Last year, an automotive supplier client of CAPS, a division of Kingway Material Handling (Exeter, N.H.), needed to start sequencing its parts for a Japanese automotive client that was starting to sequence its vehicle production. The supplier knew pick-to-light (PTL) systems could help operators pick quickly and accurately. However, the systems are computerbased, expensive and generally used for order-flow control. Both the supplierand CAPS thought a simplified version-of the system would work well for automotive sequencing.
CAPS responded with the PTL Workstation, a rugged, programmable logic control (PLC)-based system tailored to manufacturing and assembly environments. Operators scan a part or assembly number at a workstation. The scanned data turns on lights that denote the items to pick. Options include turning lights on in order, turning lights off after "n" seconds, displaying a pick quantity, blinking lights, keeping bin inventory or statistics, setting parameters for workstation robots, and more.
The PLC can have pick data stored in its memory for each part, retrieve data from the scan of a radio-frequency tag or PDF barcode, or feed pick information from an external system. The system includes a PC-based configuration program that manages the system. Greg Ivins, an application engineer at CAPS, says the system can be reconfigured quickly and easily. The PLC is easy to setup. The workstation hardware layout can be quickly changed.
Containers and Racks
Generally, automotive plants no longer construct large components and assemblies like front ends and engines on the plant floor; suppliers assemble these items. Material handlers are offering suppliers containers and racks made of lighter and stronger materials with more and better protective dunnage. Some of these containers even have built-in safety and ergonomic features like drivemotors and hydraulic lifts that move large components such as transmissions right to workers.
Sequence containers and racks are not built for density, but are designed for easy loading and unloading, says Todd Wooden, sales and design, Griswold Manufacturing and Engineering (GME) (Union City, Mich.). Workers can remove parts faster from less dense containers, he adds. GME's new ergonomic part indexing container (EPIC), is automated with drive motors and belts that bring parts, such as body panels, to operators. The automation gives the EPIC rack ergonomic and safety advantages. Workers do not have to walk in and out of containers and there are fewer injuries with the elimination of equipment like swing arms.
Because automakers broadcast what parts they need only hours before they want them, suppliers' lead times are shorter. As a result, containers have to meet the needs of the supply chain as well as the plant floor. "There are more standardized, pigeonhole type containers [in use today]. They used to be racks. Now, they are getting lighter and less expensive than racks," Orbis' Saladin says. Orbis Maximus is a 38 x 45 x 50-inch pigeonhole container. This type of container has several advantages; workers can easily slide parts in and out of it, and it can handle different types of parts easily.
Other sequenced parts like mirrors and headlamps are packed in totes that have molded-in handles to facilitate lifting. They carry about 35 to 28 pounds.
Orbis and Buckhorn Inc. (Milford, Ohio) both have 48 x 45 x 50-inch containers with hydraulic lifts to ease picking from lower levels. Buckhorn recently added a new half-size bin to its bulk-box line. The ProPack is a lightweight, 48 x 25 x 26-inch box that is approximately half the width of a standard 48 x 45-inch bulk box. The smaller size was designed to conserve space along assembly lines and other areas where space is a premium. The smoothsided, stack-only container stores long and odd-sized parts to 500 pounds. It perfectly cubes 53-foot trailers, reducing freight and storage costs.
Buckhorn also has three new Transport Tubs in extended lengths that are suitable for odd-shaped items like manufactured assemblies. The 48-inch wide tubs are available in three lengths: 57.25-, 64.5- and 70-inches with heights of 17.5- and 19.6-inches. The one-piece design handles loads to 2,000 pounds. All sizes have a center steel base runner for added strength that is said to be easy to remove for recycling.
Guided Vehicles Deliver
Automated-guided vehicles (AGVs) are fast becoming the preferred transport for assembly-line deliveries. In automotive sequencing applications, AGVs and smaller self-guided carts (SGCs) carry sequenced components like instrument panels, front-end modules, and seats to assembly lines.
Members of the Automated-Guided Vehicle Systems (AGVS) Product Section of the Material Handling Industry of America (MHIA) (Charlotte, N.C.) report that new and expanded systems business for the first half of 2004 grew from 47 systems in the first half of 2003 to 72 systems in the first half of 2004. Dick Ward, MHIA's AGVS Product Section managing executive, says the increase can be attributed to several factors including acceptance and greater maturing of the technology.
Greg Pachuta, a Mich.-based sales manager for FMC Technologies (Chalfont, Pa.), says the automotive companies are working toward automating their entire processes. FMC Technologies recently introduced a SCG that can
carry differing load dimensions and be used for a variety of applications including tow, assembly and material delivery. The carts are laser-guided and are directed by reflective tags placed on columns in facilities.