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Cell Culture PUBLIC ACCESS

Redesigning a Plant Along a Cellular Manufacturing Concept Helped to Turn Around a Troubled Company

[+] Author Notes

Associate Editor.

Mechanical Engineering 123(03), 56-59 (Mar 01, 2001) (4 pages) doi:10.1115/1.2001-MAR-1

This article focuses on Tribon Bearing Co. plant in Brook Park, OH, a manufacturer of discrete carbon composite parts and shapes that had been plagued by problems that threatened its existence. The old Tribon plant was a traditional manufacturing setup, in which operations were highly compartmentalized. Equipment was arranged according to purpose and job functions were narrowly defined. The plant’s production control manager, there was plenty of distrust and bad feelings between front-line management and the plant floor workforce. Workcell leaders work with manufacturing engineers to develop a process for a new product or to improve on an established process. Each manufacturing engineer is assigned two or three product lines. If a cell leader determines that a process change saves time or money, she/he will make it a permanent change. The manufacturing engineer makes the quality department aware of what the workcell is doing, and the quality department signs off the change.

One day in the early 1990s, employees of the former Tribon Bearing Co. plant in Brook Park, Ohio., owned at the time by Pure Industries Inc., received a wake-up call. Tribon was a manufacturer of discrete carbon composite parts and shapes. The plant had been plagued by problems that threatened its existence: Product flow was erratic, work-in-progress was through the roof, quality was poor, and accountability was missing.

Making matters worse, this was during a downturn in the aircraft industry, a key market. Around this time, General Electric Aircraft Engines, a major customer, was pushing its recently christened “supplier excellence” program and was auditing the company’s inventory turns and scrap rates for its supplier rating system.

“We knew we had to do something,” said Mark Schmeckpeper, who at the time held various engineering and sales positions at Tribon. That something was an attempt to shed its traditional manufacturing practices and adopt radically different cellular manufacturing techniques. Eventually, the plan would involve a complete redesign of the physical plant layout and recasting of job skills and functions to form the backbone of a lean and flexible manufacturing operation.

A cell worker performs the final quality check on a part at a coordinate measuring machine. Workcell operators inspect parts during manufacturing, eliminating bottlenecks at end-of-line inspections.

Grahic Jump LocationA cell worker performs the final quality check on a part at a coordinate measuring machine. Workcell operators inspect parts during manufacturing, eliminating bottlenecks at end-of-line inspections.

It was a tall order that would take years to fill. The old Tribon plant was a traditional manufacturing setup, in which operations were highly compartmentalized.

Equipment was arranged according to purpose and job functions were narrowly defined. The plastics and machining departments were located apart from each other, separated by a hallway running down the center of the building, Schmeckpeper recalled.

Parts were molded in one area, then put into bins and moved to the other part of the building, where they would be machined. “Each area had different supervisors, and it was almost like two separate companies,” he said.

Trying to get to the root cause of problems was difficult. “If something went wrong in molding, you wouldn’t discover it until it was at machining,” he said. Camaraderie didn’t extend beyond the department walls, leading to finger pointing when problems occurred.

According to David DeBrino, the plant’s production control manager, there was plenty of distrust and bad feelings between front-line management and the plant floor workforce. “It was ‘we’ and ‘they,’” he said. “Quality had its own little area; manufacturing had its own area, and it was tension with everybody. I’m trying to watch the material flow through, but nothing was moving.”

DeBrino said the plant was shipping only about 30 or 40 percent of its product to its customers at the time. The decision to move to cellular manufacturing was largely an attempt to streamline material flow and get product out the door.

In April 1992, Tribon—now named DuPont Tribon Composites—was acquired by E.I. DuPont de Nemours Co. of Wilmington, Del. Following the acquisition, there was a two-year period during which the production of the Tribon facility was integrated with that of DuPont’s Pencader Vespel parts and shapes plant in Newark, Del. Despite its decision to experiment with cellular manufacturing, Tribon, now referred to internally as DTC, continued to be troubled by poor customer service and lack of profitability for the next two years.

In 1994, the plant installed its first workcell, taking its first real stride in remaking itself into a flat organization modeled on the workcell concept, according to Parmod Sharma, the facility’s site manager, who played a key role in engineering the change.

Each workcell was to be devoted to one product line, produced by teams equipped with a broad set of skills. By the end of 1996, the plant had installed six workcells. Sharma said that the plant’s fixed-cost productivity improved by 100 percent in three years and on-time delivery increased more than 75 percent during this time.

Yet the changeover, although dramatic, was still being constrained by the layout of the building, which lacked broad, open areas. The six cells that were installed were relatively small, and there was little space in which to expand. To make the most of the cellular manufacturing concept, DTC would need a new facility—one that eliminated walls on the manufacturing floor and promoted interaction among cell teams.

DuPont agreed to provide DTC with a new facility—one that would be designed according to DTC’s specifications to implement manufacturing cells and allow, room for expansion. The new plant, located in Valley View, Ohio, was completed and occupied at the start of 1997.

The workcell leaders designed the layout of the new facility. When it was ready to be occupied, Sharma met with the leaders in the conference room at the old factory. Sharma posted a blueprint of the new one on a large cork-board, and asked the cell leaders to lay out their workcells, recalled DeBrino, who was at the meeting. “So we sat there with pushpins, with little designs of the machines that were equivalent to their size, and laid them out.”

The workcells at Valley View are laid out in the center of a large, open manufacturing area. Support functions are located around the perimeter: chemicals on one side; offices on another; shipping, supervisors, quality analysis, and maintenance on another, with a fourth area open for future expansion. The layout reflects the philosophy of the plant, Sharma said. Machining and molding action are at the center, while support functions are along the sidelines. The only part that is truly separate is the chemicals area, which contains toxic materials.

By the end of the week of the move, the Valley View facility was in full production. Shortly after completing the move, the plant had a 50 percent growth in the number of orders that it took, recalled Sharma, who said that the workcells were essential to meeting the surge in demand. Between the move (in early 1997) and March 1998, the plant added three more cells.

The carbon bearing workcell, which machines and assembles close-tolerance carbon bearings, houses many functions: CNC turning, CNC machining, CNC form grinding, lapping, honing, and assembly.

Grahic Jump LocationThe carbon bearing workcell, which machines and assembles close-tolerance carbon bearings, houses many functions: CNC turning, CNC machining, CNC form grinding, lapping, honing, and assembly.

The workcell layout at Valley View was a radical change from the old building. But perhaps the bigger challenge was to gain the trust of the plant floor operators and reorganize the workforce into cell teams.

Four manufacturing supervisors who ran the shop under the old system were removed. Cell leaders were chosen on the basis of experience and leadership qualities. Sharma invited the prospective cell leaders out to dinner to sell them on the idea of workcells, DeBrino recalled. “Try to picture nine people, plus us, sitting at a dinner table with nobody talking. These guys were like, okay, you show me how we are going to control it. And we started walking them through it.”

The conversion to cellular manufacturing required plant floor operators to learn new skills. Skill sets are assigned levels, from one to seven. The cell leaders document on-the-job training, which takes place when the workload allows. Pay incentives are provided to encourage operators to learn new skills—even those skills that would, under the old system, earn less. “That’s when we found out who wanted to do the cells,” said Bill Bidak, cell leader of the Polybon product. “In my cell, we had mostly machinists. A machinist who can learn molding gets more points and can earn more money.”

Efforts are made to provide cross training whenever possible. The plant has instituted a skill rating system to ensure that employees acquire a wide set of skills to perform, ideally, any job in the plant—molding machines as well as lathes, for example. Sharma claims that 90 percent of the plant-floor personnel can perform any job required.

The Polybon-S workcell molds, machines, and assembles close-tolerance parts of sheet molding compound. Typical steps include compression molding, form grinding, lapping, milling, and precision drilling.

Grahic Jump LocationThe Polybon-S workcell molds, machines, and assembles close-tolerance parts of sheet molding compound. Typical steps include compression molding, form grinding, lapping, milling, and precision drilling.

One payoff to cross training is added flexibility, according to John Frederick, cell leader of the Trilok CG product. “Depending on the volume of work, if one cell is shorthanded and we can spare somebody, we will put him over there,” he said. The same holds true for each other’s equipment. The flexibility has eliminated a source of bottlenecks, said Frederick, by allowing a replacement to fill in for an operator who may fall sick.

The added flexibility encourages a certain amount of movement between workcells as the workload increases and new openings occur. But, usually, workcells maintain a core group of people who have the versatility and experience to handle any job in the cell. Workcell leaders communicate with each other often, meeting every week to address issues or potential problems.

In the view of Rob Wilke, cell leader of the Polybon L product line, cellular manufacturing has increased efficiency dramatically. “Our through-time, from start to finish, is a lot faster. Also, we were able to cut down our scrap rate, and on-time delivery improved greatly.” His cell handles every step in making his product: raw material, impregnating resin, molding, machining, inspection, and shipping.

The biggest benefit of cellular manufacturing is product quality, Sharma said. Quality planning, people inspecting their own work, and a sense of ownership of the item they produce have made the difference, he said. The scrap rate of the Tribraid product—a carbon-reinforced polyimide that accounts for about one-third of DTC’s sales—dropped from about 20 percent to approximately 5 percent.

Quality inspections used to be handled by a separate department, after the parts were completed. That system presented a major bottleneck, said DeBrino. Weeks could pass before parts were inspected, and parts could be rejected and sent back for rework. With the workcell manufacturing system, that job has been largely brought inside the cell. Inspection is done after every step in the manufacturing process in the workcell, eliminating the need for end-of-line inspections. Inspection samples are taken and signed off at every stage. An outside quality department still exists to provide quality audits, check paperwork, and calibrate gauging, Sharma said.

A well-documented inspection process, taking place in the cell, is critical to making the cellular manufacturing technique work, Sharma said. “Quality has got to be in the package that is being produced.”

The autonomy of the cells provides a work environment conducive to continuous improvement, eliminating hurdles standing in the way of implementing new ideas. “Before we got cell manufacturing, if we wanted to make a change, we had to go to the supervisor,” said Frederick. “He had to check with his boss, and they had to justify whether they could implement it. Now, we don’t have to go to a boss, we just go ahead and do it.”

Workcell leaders work with manufacturing engineers to develop a process for a new product or to improve on an established process. Each manufacturing engineer is assigned two or three product lines. If a cell leader determines that a process change saves time or money, he will make it a permanent change. The manufacturing engineer makes the quality department aware of what the workcell is doing, and the quality department signs off the change.

New processes are developed in the manufacturing cell, rather than in a separate area, which has helped workcells scale up to production easier and has improved on-time delivery, said Sharma.

A cell worker in the Polybon-S workcell, which manufactures chopped fiber-reinforced parts and shapes, inspects his work on an optical comparator. In-cell inspections have eliminated bottlenecks.

Grahic Jump LocationA cell worker in the Polybon-S workcell, which manufactures chopped fiber-reinforced parts and shapes, inspects his work on an optical comparator. In-cell inspections have eliminated bottlenecks.

Workcell leaders schedule the workload in their cells. The leaders react to the customer’s request date, which is different than the usual practice of giving customers an acknowledged due date, said DeBrino. “If John [Frederick] gets a call from a customer who says he needs 1,000 parts tomorrow, he will scramble to get the 1,000 parts by tomorrow. If he can’t supply them all, he will give him something tomorrow and a commitment a week or two later.”

Most preventive maintenance is also performed in the workcells. A separate maintenance department still handles certain specialized jobs, such as working on an electrical panel, or major jobs.

All vital statistics—safety, scrap, tooling use, inventory, and general supplies—are measured monthly by the cell leaders and posted in plain sight on the side of each workcell.

At the time of the sale, the Tribon plant had total revenue of $10.6 million and employed 106 people. Valley View installed its last cell in 1998. Today, it is a $31 million business with 11 workcells and a headcount of 140. It is also a winner of the GE Supplier Excellence award from GE Aircraft Engines. When GE requested cost reductions of 5 percent a year, said Sharma, DTC was able to comply while maintaining profits.

Ronald Lee, the Vespel global operations manager and Pencader site manager, whose responsibility extends to Valley View, plans to extend cellular manufacturing to other facilities producing Vespel parts and shapes. Pencader started up its first cell in March 2000. Lee saw immediate improvements: “Production capacity increased by 45 percent; equipment reliability increased from 45 percent to 83 percent; yields increased from 85 percent to 97 percent due to lower scrap rates.” Most importantly, product delivery performance increased by 34 percent and manufacturing cycle time decreased by 70 percent.

Pencader is a 33-year-old facility, so it will require plenty of dismantling and rearranging of physical assets. However, Lee sees a bigger challenge at Pencader in convincing plant operators to break out of their narrow functional roles and expand their capabilities.

“In terms of seeing results, the real change is the people change,” said Lee. “You can buy as much capital equipment as you want, but if your people don’t understand the business and the customer needs, you cannot get those results.”

As with Valley View, the plan at Pencader is to get people to acquire the skills to perform every manufacturing operation. To accomplish that, the plant made changes in pay scale and incentives—but also heightened its expectations. “You have to know equipment, have certain behaviors, know how to read prints, know how to use micrometers,” he said. “They have to know the top five customers, and know everything about them.”

Lee said that the business also has plans to expand the workcell concept to Vespel plants located in Mechelen, Belgium, and Utsunomiya, Japan, by the third quarter of this year.

Copyright © 2001 by ASME
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