Nissan Motor Manufacturing Corp. has two paint shops. The first, System 1, dates to the construction of the Smyrna, TN, facility, which opened in 1983. It paints the Nissan Frontier pickups and the Xterra SUV. The second paint shop, System 2, is a newer, water-borne system, built to paint the Nissan Altima midsize sedan in 1992. This, of course, would beg a comparison. But rather than delineating their differences, it's probably most important to mention their biggest similarity. According to Tom Collins, director-plant manager Paint Plant, they both regularly post 96 to 98% first-run numbers. "We don't have quality troubles here," he says, "We watch our systems, by constantly maintaining them and making sure our people know what they're doing all the time." But what does this really mean? Surely, there are paint shops in other plants that "watch their systems" perform with less impressive production numbers.
|After priming, a quality inspection is made by line operators. If possible, they use knives to knock off imperfections rather than sanding them out. Knives do the job quickly without creating dust.|
Part of what gives Nissan its edge is its history. When they built System 1 in the early 80s, they designed it with the combined expertise of both Japanese and American manufacturing managers. This led to a heavy investment in robots and automation, such that approximately 90% of the paint applied in System 1 is done automatically. So when they set out to build System 2, they had years of experience working with their robots. (Note: System 1 is still using the same Fanuc robots they started with. They have, of course, been regularly rebuilt.)
From the beginning, operational knowledge in the paint shop has been well documented, first in hard copies, now in a computer database. When Nissan built the second paint shop, they used this knowledge. One result is that System 2 is much smaller and more compact than System 1. This was achieved, in part, by moving all the ovens to the same end of the line (which also made the rest of the line much cooler; in the summer, they're grateful).
It was also decided that paint application in System 2 would be fully automated. Robots were deployed, but this time, programmed to move along with cars. The robots paint each body without indexing, resulting in faster cycle times. Since the robots always know where the body is, if the line stops, the robot will also stop, but continue the paint cycle until finished. This keeps paint quality consistent. Management attributes the ability to execute this complicated programming task to the years of experience working with similar robotics.
Other "lessons learned" include something as simple as sequencing vehicles to save paint. While the ability to paint each car coming down the line a different color may have seemed clever for the people on the early tours of Smyrna (and a misplaced source of pride for the paint shop), it wasn't cost effective. Collins likes to paint cars in blocks of up to 50 at a time. That saves paint, as there is less wasted purging the equipment.
Shop Floor Management
|Behr paint bells spray an Altima. The paint shop is fully automated; any areas of the car that the bells don't get, robots will.|
Rusty Krawchuk, department manager, Altima Paint Plant (System 2), adds another twist to the comparison of the two paint shops. He explains that when System 2 was launched, all the managers went to Japan for a three-week training in shop floor management. They came back to Smyrna and instituted what was now their system. Once the System 1 people saw how System 2 did things, they decided to implement a shop floor management program of their own.
Krawchuck identifies a number of things that make System 2's system work:
- Operators are the technicians on System 2. They do approximately 90% of the monitoring and maintenance, "everything except rebuilding the bells" (maintenance does that). This includes programming and running the equipment; however, management and vendors still set the parameters. The key here is continuous training; operators are always fully trained before they're expected to do a job, and continuous training helps keep them focused.
- Every shift begins and ends with a quality meeting. Department managers identify issues from the previous shift and plan operations for the current shift. The most important defect item is always identified and worked on first, until it is solved. Then other defects are dealt with, in order of importance.
- All planned maintenance operations are always performed. System 2 has two top-coat booths. Every shift, both booths run for about three hours. Then operators take one of the booths down for scheduled maintenance, which lasts for the rest of the shift. Both booths then resume at the beginning of the next shift.
- Two-day long involvement circles have worked twice monthly since the paint shop opened. These are never missed. (It is important to note that on the final assembly line, Nissan prohibits more than one hour of overtime per day and no more than one Saturday of overtime per month. This has the effect of limiting the amount of overtime that is used everywhere else in the plant. Suffice it to say that the paint shop doesn't run overtime to get its work done.)
- Visual displays of progress and accomplishment are prominent. There are several boards for monitoring quality assurance in the paint shop. Another board lists all the 100% first run shifts since System 2 started.
- Problems are solved when and where they happen. If a defect is spotted, it is solved up the line where it occurred, rather than being fixed downstream. Collins describes the program very simply: "If something goes wrong, you fix it; you don't `Band-Aid' it."
The Environment & Money
|Robots move along with the car bodies, painting each moving body without indexing. If the line stops, the robot will also stop, but will still finish its painting cycle. this keeps paint quality very consistent.|
Like other auto manufacturers, Nissan has implemented an ISO 14001-compatible environmental management system (EMS). Part of this program is a "zero-to-landfill" initiative that most recently resulted in the change to a lead-free, high edge electrocoat process. (Lead from the two e-coat tanks was the last hazardous waste to be eliminated at Smyrna; the facility is now completely free of hazardous wastes, according to Collins.) Over vacation shut-down in July, 1999, Nissan drained both of its electrocoat tanks to switch to the system that it had been trying out in its service parts tank since the previous Christmas. This new technology is supplied by PPG (which also supplies the water-borne system and the primers; BASF supplies the solvent-cut top coat).
The uniqueness of this new system isn't as much that it's lead-free, however, but that it's high edge. "We have chosen to go to a 30 rust spot—an almost 30% improvement in corrosion protection—on a knife edge," says Collins, "We are the first ones to use this technology, period. There is no other car company using it right now."
This is part of a focus on value that has previously involved such decisions as priming in color. While it would be cheaper for Nissan to prime everything the same color, Collins and his engineering counterparts feel that the greater chip protection offered by top coat-matched primer is a value-added operation. In fact, on the Altima, an extra coat of chip-resistant top coat is added to the nose of the hood. Once again, this costs money, but adds value.
Instead of saving money by removing value, cost savings are sought in other areas. Overspray is one waste that Krawchuck and the involvement circles have attacked, by improving the programming of the robots. Another area they are working on is body sealant application. Although currently a labor-intensive manual operation, Krawchuck is working on programming the robots they already have to do the additional work. This will offer cost savings by giving them greater control over the application of sealant material.
Unfortunately for Nissan, saving money has indeed become an institutional priority. Fortunately for the paint shops, their systems allow them to continue to find ways to save money, without hindering their ability to focus on their mission statement: "To produce the highest quality vehicles sold in North America." Nissan implemented a company-wide cost cutting program called TIGER (Team Impacts Generate Earnings Recovery) in the wake of their debt problems to help get some black back into the books. For the people in paint, this just means continuing to get the black (or silver, or blue...) onto the cars.