Canadian Plastics

Spreading the lean gospel:

By Rebecca Reid, associate editor   



Buzz phrases such as lean manufacturing and Six Sigma have been hovering around the manufacturing industry for ages, but this doesn't mean the ideas behind them don't hold merit....

Buzz phrases such as lean manufacturing and Six Sigma have been hovering around the manufacturing industry for ages, but this doesn’t mean the ideas behind them don’t hold merit.

In fact, because the concepts have stuck around for so long means companies implementing these principles are benefiting both fiscally and culturally.

Lean manufacturing is becoming a way of life at the Windsor, Ont.-based Air Fuel Modules Division of the Powertrain Group at Siemens VDO Automotive Inc. Although it has been several years since the Division first implemented lean principles, the company is still adjusting to the radical cultural shift necessary for lean manufacturing to work.

“Three to four years ago, we recognized that we needed to do something different,” said Todd R. Bested, director, strategic manufacturing and product improvement in the Air Fuel Modules Division, Powertrain Group, Siemens VDO in Windsor. “We realized for us to last long-term, we needed a quantum leap in productivity.”

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The price pressures from the original equipment manufacturers (OEMs) are enormous, he explained. With resin prices increasing drastically, and with cost increases being passed to the Tier 2 manufacturers from the OEMs, meeting cost reduction targets has become more challenging, he said.

Before implementing lean, Bested said the Air Fuel Modules Division experienced 10 to 12 per cent value-added improvements each year for several years.

“Lean is the only way we can now achieve a 10 to 12 per cent cost reduction in a year,” he noted.

After kickstarting the project at its Windsor, Ont. plant three years ago, the Division has since applied lean principles to its other injection molding plants in Tilbury, Ont., Telford, England and Santa Catarina, Mexico.

Each of these injection molding plants is unique, processing different components at different volumes, but the same lean principles are working to make each facility more efficient and cost-effective.

The Air Fuel Modules Division is also gradually spreading the gospel to its other 11 (non-injection molding) plants around the world.

SPREADING THE GOSPEL

But change didn’t happen overnight. In fact, it took 18 months until it was obvious that lean manufacturing would take the Air Fuel Modules Division to where it wanted to be, Bested said.

But they had one crucial thing going for them — commitment to the project from upper management.

Kevin Burke, CEO of Siemens VDO Canada was involved right from the start, which is one of the main reason the company’s transformation to lean was successful, he said.

Also, instead of paying expensive consulting fees, the Division decided it wanted to cultivate expertise in lean principles among its own staff.

After choosing to model its lean philosophy on the Toyota Production System, the Air Fuel modules division formed a ‘lean team,’ comprised of people from all areas of the business, including manufacturing, engineering and finance.

Members of the lean team and upper management attended the University of Michigan where they completed a certificate in lean manufacturing.

Paul Howlett, lean manufacturing coordinator, Air Fuel Modules Division, Powertrain Group at Siemens VDO, was one of the individuals who completed the certification. He and Donna Pocock, coordinator for production systems, at the Air Fuel Modules Division, Powertrain Group, Siemens VDO, are the Division’s lean missionaries, responsible for teaching lean principles to the Division’s other 11 locations.

MANAGING CULTURAL CHANGE

Cultural change is difficult, Bested said, especially amongst the senior manufacturing employees.

“Before we’d go in and conduct a lean exercise, and the plant managers would say ‘that’s nice, but let me go back to running my business,'” Howlett said. Essentially, the managers didn’t feel they had time to implement the lean principles, but the Air Fuel Modules Division had to force some cultural change by designating certain employees at each location responsible for lean.

“Overproduction is the hardest to eliminate,” Pocock said. “The philosophy there is that the more you make, the more productive you, but that’s not the case if no one’s buying all the parts.”

Each year, Pocock and Howlett revisit each of the Air Fuel Module’s locations and conduct exercises called Value Stream Mapping (VSM) and gap analysis.

VSM is defined as a methodology of identifying improvement opportunities within any manufacturing system.

Howlett said this exercise helps them discover areas where they could make improvements in their manufacturing processes.

Essentially, every staff member involved in a process participates in a meeting where they visually map out all the steps involved in bringing a product to market. Pocock and Howlett said through this exercise, all employees have an opportunity to provide feedback and voice opinions.

Gap analysis determines the gap between where the company is now, and where the company wants to be, in terms of efficiency and productivity.

“We’re building on successes by using tools and moving towards a cultural change,” Howlett explained.

Bested said lean manufacturing at the Air Fuel Modules Division was a two-fold philosophy. The first aspect was to resolve current manufacturing inefficiencies and to implement lean principles for all new programs coming in, and the second was changing the business processes involved.

The transition to lean didn’t happen overnight and it’s still not 100 per cent.

“The first couple of years it was slow because people at the plant didn’t have the time or the people dedicated to work on implementing changes,” Bested said.

Another issue at each plant was the accuracy of the tracking system. Management would pull information from the tracking system, which would detail the productivity and throughput of the plant. It usually wasn’t accurate, so then we’d have to go get the real story from the manager, Bested said.

Now, in each plant, next to each production cell, there is a display board, which the plants use as benchmarking tools. At one injection molding cell in the Windsor plant, there were five pyramids on each display board. The pyramids are used as calendars, divided into grids, with each day getting their own cell. Each pyramid measures one of five variables: Health and Safety, Quality, Material Productivity and Employee Participation.

For example, with material productivity, if targets were met on September 21, then a green sticker is placed on the pyramid calendar for that day. If productivity targets were missed slightly, then a yellow sticker was used. If targets were drastically missed, then a red sticker was used.

Just by glancing at the display board it’s easy for everyone and upper management to visually get an idea of how the plant is running, and where improvements need to be made, Howlett said.

FROM ‘PUSH’ TO ‘PULL’

On the manufacturing side, Windsor was the first of the Division’s plants to trim the fat. Starting in fiscal year January 2002, the move started through a series of projects, which incrementally improved and streamlined processes.

But the transformation to lean is never over — the thing about lean manufacturing is that it isn’t just a single project, Bested explained. It’s an ongoing project that never ends because there is always something that can be improved.

At Windsor — which processes about 1.2 million units annually — it involved a plant-wide reorganization, switching from a traditional ‘push’ system to a ‘pull’ system, Bested explained.

Prior to going lean, the plant followed a traditional ‘push’ system: it molded in one spot and assembled in another, Howlett explained. And these plants were not close together.

Parts would be molded at the Windsor plant, transported in trucks to a plant in Fort Shawnee, Ohio for assembly, and then transported to the client in Buffalo, N.Y. by trucks.

T
he solution seemed obvious: move assembly in-house to Windsor.

In January 2002, the Division made its biggest step towards lean: it closed the Fort Shawnee plant and restructured the Windsor plant to accommodate assembly, Howlett said.

The Division made similar changes at its Santa Catarina location.

The Air Fuel Modules Division in Santa Catarina, Mexico used to deliver an air intake system for Daimler Chrysler’s 5.7V8 hemispherical engine to the automotive manufacturer in 33 pieces. This meant Daimler Chrysler had to assemble the part itself. By implementing lean principles, both the molding and welding of the parts was brought in-house to the Santa Catarina plant. Now it delivers the air intake system to Daimler Chrysler in two pieces.

Moving assembly in-house also helped the Division adapt to new trends among automotive companies.

“The trend for the auto industry is to buy larger and larger pieces, and this an area where lean manufacturing is being applied specifically to injection molding,” said David Geran, Asia business director, Siemens VDO Automotive China based in Shanghai, China.

While these parts are produced in Mexico, the program was engineered and designed in Canada. The Air Fuel Modules Division moved production to Mexico because of the location of the customer, Geran said.

PRODUCTIVITY GAINS

Going lean has also helped improve working conditions at the Windsor plant.

In January 2002, the Windsor facility was running seven days a week, with a 21-shift schedule. Lean has allowed the plant to shift the schedule down to five days and 15 shifts.

Additionally, in April 2003, the Windsor plant redesigned its assembly cell from a palletized conveyer system to a U-shape, which the Division dubs ‘continuous flow.’

With a palletized system, if a customer wants to add a component, you have to add a station, which would mean re-organizing the entire cell and hiring an extra person, Howlett explained.

With the U-shaped design, molding, welding and assembly cycle times were balanced so parts would flow continuously through the plant, with no bottlenecks, Bested said.

Moving towards a U, let the Division reduce floor space, from 4,040 sq. ft. to 2,075 sq. ft., spend less money on capital costs from 2.2 million euros to 1.5 million euros, reduce the number of direct operators from 10 to seven. And the equipment lead time was cut from 40 weeks to 32 weeks, Bested said. And this was only the Division’s first attempt at continuous flow, he added. There have since been further improvements. (see Chart on page 16).

“You have to have a vision for people to follow, and lean is part of that vision,” Bested said. “Some organizations see lean as a tool but for us it’s a philosophy — a business philosophy.”

Metric Original Design Direct Run (Most Manual)
Capital (CDN $) 2.2 Million 1.5 Million
Floor Space 4,050 sq. ft. 2,075 sq. ft.
Direct Operators 10 7
WIP Levels 1.5 days or 1950 pcs. 1 hour or 54 pcs.
Equipment Lead Time 40 weeks 32 weeks

Gains made switching from a conveyer system to continuous flow U-shaped design. Further gains have been realized since the adopting this configuration in 2003.

TURNING A ‘LOST’ PROCESS INTO A ‘CORE’ PROCESS

Implementing lean manufacturing principles allowed the Air Fuel Modules Division of the Powertrain Group at Siemens VDO Automotive Inc. in Windsor, Ont., to resurrect a formerly expensive process — Lost Core Injection Molding — and make it cost effective.

Prior to producing air intake manifolds for the Dodge Magnum using the Lost Core process, the hollow parts were produced by injection molding numerous, differently shaped components. Then they were placed together on a jig and vibrationally welded together, explained David Geran, Asia business director, Siemens VDO Automotive China based in Shanghai, China.

However, when the customer wanted better engine performance. Paul Howlett suggested moving back to the Lost Core Process because within complex shapes such as an air intake manifold, air flows better if the part is processed as one piece. This would translate into better performance for the customer.

Howlett said his idea was initially met with skepticism because Lost Core was on its way to extinction. But after building a sound business case and solid design plans, the customer and Siemens were convinced.

By developing this program using lean principles, the Air Fuel Modules Division was able to make it an affordable and efficient process. Not to mention that vibrational molding was starting to take a financial toll on product production. Because the part was comprised of many components, more machinery and molds were required, ramping up costs.

“Both are cost-competitive,” Howlett said. “But more shells increases the amount of tooling you need to do, so there is a trade-off. But the customer needed more performance and Lost Core provided that.”

However, the Lost Core process used to produce the air intake manifold is slightly different from the traditional method.

In the old school approach to Lost Core injection molding, which was created by Porsche in the mid-1980s, according to Geran, a core was created out of compressed sand, which represented the internal geometry of a finished plastic product. Then the air intake manifolds were molded with aluminum, not thermoplastic.

After the part was molded, the sand core simply broke apart and flowed out of the part’s cavities. However, the sand cores were expensive to produce and the material could not be re-used.

Additionally, thermoplastic is currently replacing aluminum for air intake manifolds not only because it is cheaper, but also because it absorbs less heat, meaning air flows better through a thermoplastic air intake manifold, increasing engine performance, Geran explained.

The Division’s Lost Core Process involves casting a metal core out of molten tin bismuth alloy, which has a low melting temperature of 138C.

Once the core is cast, it is placed on a buffer conveyer by a robot and moved through a cooling area to further solidify.

Then the solid tin bismuth core is loaded by robot into an injection molding machine, where a glass-reinforced nylon 6 or nylon 6/6 is molded around the core, creating the part, Geran said.

After molding, the robot removes the overmolded part and places it onto another buffer conveyer where it is moved to another robot that places it in the melt out tank.

In the melt out tank, the overmolded part is immersed in a heat-modified polyglycol ether bath where the tin bismuth core melts and flows out of the plastic part. The tin bismuth is collected and re-used again in the core-casting process, which incidentally is cheaper than sand-cast aluminum, Geran said.

The hollow plastic part is then rinsed for residual melting solution and scanned by a metal detector for residual tin bismuth. Afterwards it is assembled and tested.

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