Producing a car a minute requires coordination, split-second timing, and a lot of behind-the-scenes support. Here's how GM keeps the Chevrolet Cruze assembly lines humming.
In an auto race, technicians on a pit crew must carry out their tasks in a precisely choreographed sequence to get the driver back out on the track as quickly as possible. To do that, they have to have the right materials ready in the right order and at the right time. The same could be said of manufacturing automobiles. Today's complex assembly operations require the same kind of coordination and timing to keep manufacturing running at a high volume.
Take the assembly of the popular Chevrolet Cruze, for example. Thousands of parts go into its production—parts that have to come together quickly and in a precise sequence in order for the assembly plant in Lordstown, Ohio, to meet its goal of producing one car per minute. Making sure the plant has all of the parts it needs on time and in the right sequence is the job of Comprehensive Logistics, a third-party service provider that specializes in automotive logistics.
Comprehensive operates a 640,000-square-foot distribution facility in Austintown, Ohio, which is located less than 10 miles from Lordstown. The facility's sole responsibility is to feed parts to exact positions on the Lordstown assembly lines. It receives, consolidates, and deconsolidates parts from suppliers and prepares them for just-in-time delivery to the plant. Currently, 85 percent of the parts used in the Cruze flow through the Comprehensive facility—a total of 2,236 SKUs (stock-keeping units).
Providing these types of consolidation and distribution services is a specialty of Comprehensive, which currently supports about 25 different auto production plants nationwide. The company has been serving the Lordstown plant for 11 years. Before it began providing production support for the Cruze, the facility handled parts for the Chevy Cobalt and Cavalier models that were previously built at Lordstown.
But beyond simply sorting and organizing parts, the real value that Comprehensive brings is its value-added services. For Lordstown, this includes producing subassemblies of some of the major components for the Cruze. These subassemblies will later be inserted directly into the car, saving valuable time at the Lordstown assembly plant.
A PLAN FOR EVERY PART
General Motors (GM), Chevrolet's parent company, owns the parts processed at the Austintown facility and orders all the parts from suppliers. The parts basically fall into three categories. The first consists of bulk parts, which are basic items that go into every Cruze built. The second category consists of parts that differ depending on the individual car, such as a door panel of a specific color. The last category consists of parts that require that something be done to them in Austintown, either through the site's kitting or subassembly operations.
GM provides Comprehensive with electronic data files on each type of part it requires for the Cruze. Comprehensive then creates an individualized plan for handling that part based on its dimensions, weight, origins, where on the Lordstown line it will be needed, and the minimum/maximum number needed to maintain desired levels of inventory. This information is uploaded to Austintown's proprietary warehouse management system (WMS), known as Streme. Processes in the Austintown building are then designed around those particular incoming parts.
"We engineer the layout based on the parts—where they will be stored, when they need to be picked, what value-added work needs to be done on them, which dock they will enter the building from, and which dock they will ship from," explains Trey Lyda, director of corporate services, who is responsible for the engineering design and layout at the Austintown facility.
Once a plan is in place, the facility is ready to receive the parts. GM provides advance ship notices for parts due to arrive at Austintown's 54 receiving docks. Most parts come in reusable plastic containers or metal racks designed specifically for the individual parts they hold.
Receiving personnel scan the suppliers' labels on incoming containers and conduct a visual inspection. The containers are then assigned a "license plate" in receiving, which is scanned into the Streme system. The WMS determines whether the items will be cross-docked or sent to storage areas, where they are stacked on the floor or placed into pallet racks for short-term storage. The storage areas are scattered throughout the building—either close to the docks from which the products will depart or near areas where the items will undergo further processing.
Some parts, especially those from international suppliers, arrive in cartons. These are either repacked into plastic containers for delivery to Lordstown or sent to kitting areas, where they are combined with other parts to form kits (for example, a kit that includes the pieces needed for an emergency tire jack set). The kits are then placed into containers for lineside delivery.
Austintown also provides management services for the containers and the metal racks. The company gathers empty containers at Lordstown and returns them to the vendors. Right now, there are 114 different types of containers within the container management program, and the Austintown facility handles an average of 14,000 empty containers daily.
START YOUR ENGINES
Production takes place 24 hours a day, five days a week. As parts are consumed in Lordstown throughout the day, GM electronically delivers, or "broadcasts," lists of replenishment parts it needs for assembly. Comprehensive has about 80 minutes to gather and deliver bulk parts to lineside positions in the plant. Most of these parts are already packed in containers or loaded onto pallets, so it's a matter of gathering them and placing them onto trucks that shuttle them to the Lordstown facility.
The Austintown facility has 42 outbound docks, where containers are loaded onto the trucks in reverse sequence to the order in which they will be used on the production line. Falcon Transport Co., a sister company to Comprehensive, provides the transport services using standard 53-foot trailers.
As for the tracking of materials throughout the day, the Streme system provides GM with full visibility into the status of Austintown's parts processing operations as well as products in transit. GM, in turn, shares information on inventory on hand at Lordstown so that Comprehensive can prepare for what parts will be needed next. Lordstown typically keeps only about four hours' worth of materials on site.
"Streme provides us with an animated representation of everything we have in inventory and in process in real time," says Steve Olender, vice president of information technology at Comprehensive.
Many of the parts require specific sequencing to match the build order of individual cars. In the case of these parts, workers receive picking directions via radio-frequency (RF) units. If, say, a door panel pad is needed, the RF device will first tell a worker which part to pull from a rack of panels. The worker scans both the rack and the individual part to confirm that the correct item has been removed. At that point, the system prints a parts label, which the worker scans and applies to the part. The RF device then tells him or her which slot in the 12-slot shipping rack to place the part into so that the items will be in the proper sequence for assembly. The worker next scans the slot in the rack to confirm that the right part was placed there. Conducting four scans for a single pick might sound like overkill, but Comprehensive believes it's necessary to ensure ultra-high levels of accuracy.
CHANGE IS A WAY OF LIFE
Most people would be surprised at how much continuous improvement goes on in automotive manufacturing. Engineers are constantly tinkering with the cars, making incremental improvements. As a result, there are about 150 part changes every week that Austintown has to address for Cruze production.
"The car gets better every single day. It is all part of continuous improvement, as we all want to make a better product," notes James Kriner, the Austintown plant manager.
Sometimes, though, car companies will decide it's time to make wholesale changes to a particular model, which happened this year on the Cruze. On Feb. 8, GM began producing a completely re-engineered second-generation Cruze.
In preparation for the changeover, the Lordstown operation shut down for five weeks for retooling. Among other decisions, Comprehensive had to determine how to handle each of the new parts for the Cruze, as only 161 of the 2,236 parts remained unchanged from the first-generation car to the second.
As part of the overhaul, GM made wholesale changes to its sourcing strategy. Some 70 percent of the parts in the 2015 model Cruze came from international points, with only 30 percent sourced from North American suppliers. For 2016, that is reversed—70 percent North American and 30 percent international.
Sourcing parts closer to home allowed GM to cut leadtimes while creating flexibility within its supply chain. The changes also affected Comprehensive, as it was able to reduce the amount of buffer stock it keeps on hand. Since international inventory often takes as long as 30 days to travel by water, the facility holds about 10 days' worth of inventory of internationally sourced parts. For domestic products, the facility carries just one to four days' worth of buffer stock. As a result of the change, Comprehensive no longer needs two satellite buildings formerly used to house buffer stock.
While it was carrying out the retooling, Comprehensive decided to rearrange some of the storage and processing areas at the Austintown facility. It added narrow-aisle storage and moved some of the storage and staging areas closer to the docks through which the products enter or exit the facility. This has reduced forklift travel time within the building (the facility operates a fleet of 62 electric forklifts supplied by Clark Material Handling).
"It's the detail we go into for every single part. We study our standards for time and distance to provide added productivity and to improve our processes," Lyda says.
The new generation of Cruze also requires that more parts be sequenced for specific builds than was the case with previous models assembled at Lordstown. "It affects our lineside presentation, so we looked at our own layouts to make our work more effective," Lyda adds.
SOME ASSEMBLY REQUIRED
Among the changes made during the retooling process was the relocation of two of the subassembly lines at the Austintown facility. These subassembly operations represent a major value-added service that Comprehensive provides to GM. At Austintown, workers run five production lines that pre-assemble specific sections of the Cruze vehicle. The Streme software directs the manufacturing process, acting as a manufacturing execution system.
Subassembly lines include the so-called CFRM line, which assembles the condenser, fan, and radiator module (this was one of the subassembly lines that was relocated). Another subassembly line builds the front vertical, which includes the front suspension system and front disc brakes. A rear vertical line assembles the rear suspension, rear axle, and rear brakes, while a front horizontal line produces the engine cradle.
Perhaps the most complex of the subassemblies Comprehensive builds at Austintown are the "headliners," which are the interior linings for the cars' roofs (the headliner subassembly line was the other line to be relocated). Though that might not sound like a particularly complicated component, there are actually 96 different variations of headliners for the Cruze model, depending on color, the type of visors, whether the car will have a skylight or sunroof, and the lighting and electronics packages.
As soon as it determines what headliners it will require, Lordstown transmits a broadcast message to Comprehensive describing the specific permutations for each headliner it needs and the sequence required for delivery. Nothing is built at Austintown until this message is received, as the facility operates strictly on a pull inventory system. Austintown then has two hours to assemble the headliners and deliver them lineside to Lordstown.
Once the subassembly line swings into operation, large display dashboard screens on the production floor track the units' progress. Some of the work is carried out by robots, which handle tasks like applying glue. Fixed cameras and sensors measure assembly angles and tolerances to assure that every fastener is in place and all actions have been completed properly.
Finished headliners are placed into racks designed specifically for them, with each rack holding 19 headliners. The production is carried out in reverse order so that the items needed first in Lordstown are placed into the racks last.
Overall, Austintown prepares about 1,600 truckloads of parts each week for the Lordstown assembly operation. Comprehensive is responsible for making sure that all of the parts are delivered on time, at the right place, and in the right sequence for the GM plant to turn out 1,260 cars daily, or 280,000 in a typical production year. Or to put it another way, the 3PL's job is to ensure that all operations remain solidly on Cruze control.
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