Dennis Sampey loves the new work schedule he started in February. The 46-year-old veteran of Ford Motor Co.'s Michigan Truck day shift has an extra day off and doesn't have to wait in line when he does errands in the morning. Joyce Ingraham, a 33-year-old with two young children likes it, too. She and her husband are able to work full time without resorting to babysitters or day care.

George Mink, a 61-year-old hi-lo driver who worked afternoons for years, says he'll probably stick with the new shift until he retires in five years.

To outsiders, working the new "C-crew" at Ford's Michigan Truck plant sounds like a surrealistic nightmare: long 10-hour days twice a week on the day shift and then two more 10-hour workdays on the evening shift from 6 p.m. to 4:30 a.m., changing work and sleep schedules twice a week.

Though constantly bending one's internal clock like a Salvadore Dali painting may sound exhausting and bizarre to the regular 9-to-5 crowd, many veterans of auto assembly plant shift work think it's a dream come true: It represents a lifetime of 3-day weekends and never having to wait in line at the bank or the supermarket. And Ms. Ingraham says the schedule of her previous retail job was even more difficult.

To workers on the other A- and B- crews" at Michigan Truck, life isn't much different at all: They work a 10-hour day-or afternoon-shift like they have for years and still get overtime for the last two hours of every day. The paycheck still is fat with overtime pay, but now they only work four days a week.

Long hours and night shifts have been a staple in the auto industry for decades, but work shifts that juggle three crews on two shifts over six or seven days - generally referred to as the "three-crew" system - is a relative newcomer. Although it has drawbacks, it's increasingly favored over other "alternative" work schedules, such as using three crews on three 8-hour shifts five or six days a week, or continuously running extended overtime schedules on two shifts.

To an industry desperate to improve capacity utilization - three-crew shifting can boost capacity more than 40% and still leave four hours daily for maintenance - and boost production of certain hot-selling models without adding the huge expense of new plants and equipment, it is the pot of gold at the end of the rainbow. To well-paid hourly workers accustomed to lucrative overtime pay, it is a decent compromise. And to a wary United Auto Workers union (UAW), it seems to be one of the few alternatives it has left to create new jobs without sacrificing pay or benefits. The only area where there seems to be real controversy is at Saturn Corp., where workers are divided over whether shift assignments should be permanent or rotated.

There are numerous ways to implement the three-crew, two-shift concept. Some never work Sundays, and rotate workers through each shift over three weeks. Others have a down shift on Saturday evening and another on Sunday morning. But in most U.S. plants, jobs and shift assignments are permanent and governed by union seniority rules.

The concept first was tried by General Motors Corp. in 1988 in Antwerp, Belgium. After enjoying huge success there, GM has implemented three-crew, two-shift systems at its J-car assembly plant in Lordstown, OH, Saturn in Spring Hill, TN, and light truck plants in Oshawa, Ont., and Flint, MI. GM's Moraine, OH, assembly plant, producer of the hot-selling Chevy Blazer/GMC Jimmy sport/utility models, is the latest GM plant to adopt the system. It's currently training third-crew workers and should be up to speed by mid-June. Gm's Pontiac, MI, pickup truck plant also is expected to soon move to three crews.

After studying Gm's efforts for years, Ford adopted a three-crew system last February at its Michigan Truck plant in Wayne, MI - its first alternate work schedule in North America. The move created 900 new jobs at the plant, which builds hot-selling Ford F-Series pickups and Broncos.

"Careful use of capacity seems to be one of the major ingredients of automotive success," says Sean MacAlinden, research scientist/manager of Economic Studies at the University of Michigan, explaining why three crews are catching on.

Mr. MacAlinden says GM watched Ford become a world leader in productivity in the 1980s basically by improving its old plants and adding overtime. GM, on the other hand, added lots of new factories in the '80s and now, as its market share has shrunk, is saddled with too much capacity and is considered the highest-cost U.S. producer. Wherever possible, GM would like to consolidate two factories running well below their rated production - like many GM operations are - and turn them into one three-crew plant. That's how it worked in Antwerp in 1988, and later at Lordstown and other facilities.

At Antwerp, there was 40-year-old Antwerp 1, which produced 38 Ascona cars an hour, and the highly automated 76-Kadett-per-hour Plant 2, which was much newer. Combined production was 400,000 units a year. Each ran two 7:40 shifts, five days a week. After getting union approval, Plant 1's 3,000 workers moved to Plant 2 and began working 10 hours a day, four days per week on alternating shifts. Plant 2 then began running 110 hours a week compared with 77 hours before the change.

Total operational costs fell about 20% compared with the two-plant system, and capacity utilization jumped 44%. Plant 2 started setting production records, knocking out 80 cars an hour from a facility rated at 76. The company also hired 1,400 new workers, the first new hires in nine years. That pushed hourly employment to 8,800.

Saving on labor costs isn't the purpose of moving to alternative shifts, Mr. MacAlinden emphasizes; it's solely aimed at maximizing the use of enormously expensive auto plants and equipment.

After being very wary at first, the UAW no longer opposes three-crew schedules. But there are rules: It must create new jobs and can't be used to whipsaw one plant location against another in a bidding war for new work. And companies can't use threats of plant closings to force approval of three-crew schedules. Willingness to move to a three-crew schedule reportedly was one of the chips on the table when GM chose to close an assembly plant in Ypsilanti, MI, instead of Arlington, TX, in 1992. The UAW doesn't want that to happen again.

"Alternative work schedule programs should also preserve the traditional wage payment practices on overtime, along with other provisions concerning pay for time not worked and benefit programs, while also expanding relief time, adding paid lunch periods and modifying other contractual provisions where necessary," says an official UAW resolution on the subject.

One plant where three-crew has helped both the union and company is Lordstown. An added third crew in 1992 saved the jobs of 1,500 hourly workers in an adjacent van plant that was shut down.

But adding another crew also is a very cost-effective means of meeting demand for hot-selling products, and it certainly meshes well with Ford's often-stated strategy of building new plants at "old addresses."

Adding a third crew at Michigan Truck boosts annual production capacity by 32,000 units, to 240,000. Ford spent less than $11 million in facilities and tooling for the new operation. In an era when new assembly plants can cost well over 1 billion, that's postage stamp money.

"When we talk about capacity, there are things that are available to OEMs today that we would never have considered 10 years ago, and they are not capital-intensive, they're more people-intensive," says Shamel T. Rushwin, vice president-International Manufacturing and Minivan Assembly Operations at Chrysler Corp. "And we're finding our supplier base doing the same thing. Rather than going to brick and mortar, they're going to more crews and more run time and more uptime.

"If you go back 10 years in the industry, whatever the day rate of a plant was, 1,000-a-day or 500-a-day, that's what they ran, period," Mr. Rushwin says. "Now we've become very innovative and flexible, and we've developed increments for increasing capacity. (At Chrysler) the first increment is you run the plant on straight time and shut down for breaks. The second increment, you run straight time, but with tag relief, and never shut down the line. The third increment is premium time, overtime with tag relief. The last increment is going to alternative work schedules, such as Windsor has running: 22.5 hours per day six days per week."

Despite the benefits of three-crew, two-shift operations, Chrysler and Japanese automakers have been cool to the concept.

Both seem opposed to it for different reasons. The Japanese, who have enjoyed steadily increasing demand for their vehicles for decades, have had little trouble managing their capacity. If demand taxed U.S. facilities, production was supplemented from Japan. Until recently, they have not had to shutter plants or lay off shifts to balance output with cyclical sales.

Furthermore, Mr. MacAlinden says the Japanese like to have plenty of time for equipment maintenance.

Vince Sorgi, vice president of manufacturing at Nissan Motor Mfg. Corp. in Smyrna, TN, says demand for the hot-selling Nissan Altima hasn't forced him to seriously consider a three-crew, two-shift operation. The giant Nissan facility produced 452,000 vehicles last year, and makes two other models - the Nissan Sentra and a compact pickup truck - besides the Altima. Surges in demand easily can be accommodated by simply changing the build mix and running some overtime, Mr. Sorgi says. Although the Altima is built only in Smyrna, Sentra production could be supplemented by Nissan facilities in Mexico or Japan if necessary.

However, Mr. Sorgi says NMMC is running three straight shifts in its metal stamping operation, which supplies hot-selling Nissan Quest/Mercury Villager production for the Ford/Nissan joint venture plant in Avon Lake, OH, in addition to Smyrna. But Mr. Sorgi worries about how 10-hour shifts affect workers and quality in vehicle assembly operations. Overtime shifts at Smyrna now usually are only nine hours.

That's the same concern of Chrysler's top brass. So far, the No. 3 automaker has been using three-shift operations, not the three-crew scheme, to boost capacity of its hot-selling minivans and Jeeps. "If the workforce wanted (three-crew two-shift), we'd-probably consider it ... but it's tough on people," Chrysler Chairman Robert J. Eaton told WAW last winter.

In the past, Dennis K. Pawley, Chrysler executive vice president of manufacturing, has been quite vociferous in his opposition to three crews working two 10-hour shifts.

"My personal feeling is that you build your best quality when you are working a standard 8-hour day where people don't wear out," he said in an interview several years ago. "If you're working four 10s, yeah, you're only working four days, but 10 hours is 10 hours."

The knock against Chrysler's, three-shift system, of course, is that it allows less time for equipment maintenance and repair than three-crew, two-shift operations. But Chrysler has been doing it for over three years with few problems. The key is a truly heads-up maintenance organization, says Chrysler's Mr. Rushwin.

"It's kind of like the Daytona 500," he says. "You have a pit crew on the weekends. They go in and do the rebuilding that has to be done. During the week you have the crew that's going to take milliseconds to get things done and is very proactive in anticipating what the needs of the process are so it doesn't break down.

"It reflects our ability to apply science-based technology like thermography and vibration analysis to predictive maintenance. We've had good success."

Although the impact of three-shift schedules on machinery seems easily controllable, the impact on people of three-crew, two-shift operations is less clear. Experts at Portland, ME-based Matrices Consultants Inc., which advised Saturn Corp. on implementing its three-crew system, say humans cannot change their systems totally to be compatible with working through the night. What they can do, with practice, is adjust temporarily to accommodate night work for periods of time.

Tradition says that the longer the assignment on nights, the better. The assumption was workers would get used to it. More recent research shows, however, that most workers never fully adapt to working nights, and that can cause health problems.

This research, in part, has led to rotating three-crew schedules in Antwerp and at Saturn, where each crew switches between the day and night shifts over three weeks. In most other three-shift, two-crew arrangements, only the C-shift switches back and forth between days and nights.

It may be more healthy for the group as a whole, but many workers have found that sleep schedules are easier to adjust to than other areas of their lives, and they would prefer a permanent schedule.

One European union official complains that workers almost always end up sleeping through their "free" day in order to be adequately rested for the next shift.

It has become a contentious issue at Saturn. Unfortunately, Saturn's 8,000 employees are evenly divided over how it should be resolved. A spokesman says management and workers are now studying 34 different compromise schedules.

Management and union officials at Michigan Truck say they studied numerous alternative shift schedules but did not consider rotating shifts for their operation.

Plant manager Frank Foley and UAW Local 900 Plant Chairman Doug Howard say their biggest concerns were protecting the safety of the 900 new employees - many of whom were being introduced to an auto plant environment for the first time - and making sure quality levels were maintained while the plant made the transition to a three-crew operation. Michigan truck has been running two 10-hour shifts for years, so they say there are no inherent quality or fatigue problems with running shifts that long.

Ensuring that each shift was well-staffed with experienced veterans was not a problem: about 40% of the new C-shift is composed of senior workers from other shifts. This experience is echoed by officials at other plants with fixed schedules. Extra pay doesn't hurt; C-crew members earn a 10% premium.

"One thing that shocked the hell out of us was the amount of turnover. We expected 10% to 15%, but it was only 6.8," says Mr. Foley. Absenteeism also has improved 15%, he says.

Because the three-crew system only has been running since late February at Michigan Truck, both plant and union officials still are calling the operation an experiment. There haven't been any safety problems, but they want to study warranty reports and other longer-term quality indicators before declaring it a total success.

But after an adjustment period of six weeks or so, many workers on the C-crew say they now can bend the clock as well as Salvadore Dali. "I prefer the third shift," says Repairman Dwight Chandler, 32. "With my seniority, I could work any shift, but I get the best of both worlds on this one."