Timken tackles a lean transformation

the North Carolina State University Industrial Extension Service
Tags: lean manufacturing

A sluggish economy provided the opportunity for the Timken Company in Asheboro, N.C., to tackle the complicated task of integrating lean thinking into every aspect of the business quicker and more thoroughly than when the plant is running at top speed. When the economy recovers, the efficiencies they’ve gained will make them even more competitive, said Regis Eger, manager of operations.

In just the first few months of its lean journey, the Timken plant improved existing capacity by 25 percent, reduced manufacturing lead time by 83 percent and reported savings of almost $900,000 – a conservative figure, since Eger said only about 15 percent of the plant’s processes have been “leaned.” Another improvement can be seen in the new attitudes of the workforce and how work is done.

Scott LaPlant of Timken explains the triangle kanban system used to control batch process.

On a recent morning, visitors from four other Randolph County manufacturers toured the plant to see for themselves what Timken has accomplished. During the presentation by Timken’s lean transformation leaders and later while walking through the plant floor, the Timken employees emphasized repeatedly that the credit for change begins at the top.

When Bob Bauman became plant manager in 2008, he made it clear that he wanted the plant to adopt the Toyota Production System (TPS), the gold lean standard. The company turned to extension specialist Barrett Walker with the North Carolina State University Industrial Extension Service for help. And in the spring of 2008, experienced lean transformation sensei(teacher) Sam McPherson was selected to guide Timken through the transformation process.

McPherson immediately recognized and appreciated the support of top leadership at the site. For TPS to succeed requires “intense leadership and commitment.” He found that at Timken.

The Timken plant in Asheboro makes tapered roller bearings for Caterpillar, Volvo and Siemens, among others, that are 8 inches to 24 inches in diameter. This low-volume, high-mix output created uncontrolled inventory in work in progress. More than 250 employees work in the 210,000-square-foot facility an average of six days a week for two shifts, generally making 17,000 pieces each month. Last year’s sales volume was $180 million.

In June, McPherson led the plant’s top leadership through a lean leadership boot camp. The group decided they could best meet customer demand – the ultimate goal of lean transformation – by tackling four major challenges:

  1. Reduce manufacturing lead time and improve responsiveness to the customer
  2. Correct and complete delivery to the customer on time
  3. Reduce inventory to reduce lead time and improve operating capital
  4. Build an engaged lean culture of all Timken Asheboro managers and team members

Tracy presents Zone Control Plan.JPG

They approached these issues in a learn-and-do process. McPherson would introduce a lean concept in the conference room and the leaders would then go to the factory floor to implement it. The leaders selected weren’t just the management team, but included both engineers and frontline leaders. The work of the initial management team and lean leaders freed up other managers, engineers and front-line leaders to participate in the second generation of lean training and engage in the transformation.

For example, Tracey Bruce (pictured in the center of the second picture) isn’t a manager, but he was a lean leadership candidate for one of the lines where large batches of product were pushed from operation to operation, causing excess work in progress. He described to the visitors how they reduced lead time from six months to 30 days. A new pull system was created that pulled product from one process to another by sharing assets on a line.

Each pallet now carries enough product for two hours of work at the production cell. Hourly, an additional one hour of material is “pulled” to the production cell. A system of large colorful cards (called kanban) placed on boards at the start of each line tells everyone at a glance where the process stands and controls the production and movement of material. Three months of trial-and-error went into developing Timken’s customized card system. Now, material handlers quickly know when they need to move product from one point to another. Empty shelves nearby give a clue to how much inventory has been reduced. The process, which requires the product on that pallet to be done next, has eliminated cherry-picking of jobs, Bruce said.

Before Pull System.JPG

Before Kanban System

After Pull System.JPG

After Kanban System. Note each pallet is lot sized to one hour and a Production Instruction Kanban is located on each pallet

Note to readers: The lean terms “Supermarket” and “FIFO (First-in; First-out) Lane” are very specific Toyota Production System and lean terms and are critical control mechanisms in a pull system where true one-piece-flow cannot be achieved. Though they differ in form, both are controlled inventories of needed items used to schedule production in a pull system and are physically located at the upstream-producing process, where they can be visually managed.

This new demand-driven process requires a flexible workforce. Cross-training becomes mandatory. Lean leaders are taught a training process known as Training Within Industry Job Instruction to cross-train team members to perform critical skills. When one line is down, an employee can move easily to another and perform new duties quickly, safely, correctly and conscientiously.

Using TWI Job Instruction method to cross train.JPG

The plant has been divided into “zones” as part of its adoption of TPS. Each zone encompasses several inter-related processes, because a problem in one process often leads to problems in another. The zone leader has only one assignment: Achieve the daily production plan. In order to do this, zone leaders must maintain constant problem awareness, teach others to spot abnormalities quickly, teach others to identify the root cause of a problem, lead their team in daily improvement activities and develop permanent solutions to problems, or what they call “recurrence prevention countermeasures.” Front-line workers know to go to the zone leader as soon as they recognize a problem. By investigating problems that interrupt the achievement of the “takt production plan” each hour through the use of a Production Control and Analysis Board at each production line or cell, zone leaders and their team members are solving problems that have been preventing the smooth flow of product to the customer. As a result, existing capacity has increased 30 percent and the number of products needing rework has been reduced, on some lines by as much two-thirds.

“I thought our biggest problem in lean transformation would be to get people to support growth and sustain the changes. But the acceptance on the shop floor has been very good,” Eger told his visitors. “They’ve seen us do a lot of trial and error. We’re still working on the systems. Maybe most important, they know we’ve got to continue to do better.”

“A well known image in TPS is the House of TPS”, McPherson told the group. “The House of TPS provides the road map for a lean transformation. I could not imagine attempting to navigate through the turmoil of our current economy without having first built a foundation of an engaged lean culture here at Timken Asheboro.

“Remember, lean tools and techniques do not solve problems, they only surface them very effectively,” he said. “The solutions come from the creative thinking of our people, and to allow anyone to improve the process and better meet customer demands.”

Timken, he noted, is well on the way.

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