Cutting lead time with lean

At Cabinet Door Service, you have to go with the flow. The Salem, Ore., producer of cabinet doors and dovetail drawer boxes has created a new business model based around flow and value stream mapping.

Two years ago, The Strategic Economic Development Corp. in Salem, a local economic development agency introduced CDS to the Oregon Manufacturing Extension Partnership. In the time since, they have re-engineered the business model into what is called the CabDoor Production System, based around lean manufacturing principles.

"We're competitive on price, we offer good quality and the level of service we provide is outstanding," says CDS co-owner and production manager Cliff Stites.

One of the first benefits of the change was easy to see: CDS reduced its overall space requirement from 168,000 to 68,000 square feet. All of its manufacturing is done in 48,000 square feet, with 20,000 square feet for raw material storage.

CDS adopted the business model concept for lean. "CDS took advantage of the operational excellence they now have and have taken it to the marketplace to create an advantage," says Dave Looper, consultant with the Oregon MEP.

CDS makes doors primarily for small to medium-sized cabinet shops in the Pacific Northwest, including Boise, Seattle, Medford and Roseburg. CDS's top 100 customers have done business with CDS for an average of almost 14 years. CDS's own trucks handle most shipments. They offer guaranteed on-time delivery, a three- to five-day lead time, and a discount on the first 100 doors ordered from new customers.

Batched and dragged

"Before, we took the entire production process and broke it up into three production segments: day one, day two and day three," Stites says. "Everything would be batched and dragged into the next area. And the employees were knocking themselves out. Now that we have flow, the workflow is predictable, they do the next job presented to them, and just meet takt (interval) time.

Earlier production problems came from the business systems and processes not from employees. As part of the lean model, CDS management accepted that employees were doing the best job they could within the process.

Employees have seen wage gains and promotions. CDS put the first 30 percent of cost savings generated by lean into wage increases. And 50 percent of any additional efficiency gains go back to the employees through gainsharing.

The company also developed a compensation system that was fair and transparent. "The high performer gets the rewards and promotions are automatically offered to them first, and the lower performer stays where they are," Stites says.

Half of the performance evaluation is based on the number of jobs (cross training) in which an employee is proficient. If there are no sales orders for one cell, an employee could move to another area.

"Our goal is to get every employee to a level of being able to complete 30 percent of jobs," Stites says. "Right now, we're at about 15 percent."

Looper says that 80 percent of the workforce has Spanish as their native language, but the Oregon MEP teaches lean items using English terms.

Dovetail drawers first

Value stream mapping, the creation of flow, creating a financial and physical success that can be seen. Looper says that when MEP engages a new client, they want them to see the opportunity. "We're telling them what they've done for 20 years is wrong and the new right thing is what they need to do," he says.

"When we do the assessment, we're looking at where we can achieve a success and start the lean learning process as part of the initial training, so they can get a win under their belt and sustain it."

For CDS, this "early win" was achieved in the dovetail drawer area. "It was an overnight transformation, a huge gain," Looper says.

Closed-loop system

Processing time from raw lumber to Purewood doors ready for shipment was reduced from 48 hours to six hours with the new system. Doors are processed in skids of 15 doors. That's the takt time image (pitch), which recognizes an increment of time. The goal is 50 skids per shift.

"We have a fixed number of 34 skids in a closed-loop system," Stites says. "We don't start cutting panels unless there is a skid to put them on. Every 10 minutes there's a skid that comes off, and it goes back to (the start) of the flow.

"From the time we start chopping boards to the time they come off the orbital sander, it's five and a half hours," Stites says. "Everything's made to order. There is no finished inventory."

CDS is making 1,000 doors a day in four 10-hour shifts with a second partial swing shift. Maintenance is done on Fridays. CDS has the capacity to make 1,500 doors a day.

With the closed-loop system, barcoding at every station isn't necessary. Bar coding is still done at the start because it tells the office which orders have been put in the value stream and if there is production capacity left. Looper says that a predictable flow leads to a predictable of outcome. They know where everything is.

About half of CDS's doors are solid wood and half are plywood doors. Shaker has been a hot style. About 40 percent of solid wood is alder. Cherry is popular, maple has grown, but red oak has dwindled to about 8 percent.

Hardwood Industries in Tualatin, Ore., can provide next-day delivery for any wood requirements.

"We have a strategic alliance with Hardwood Industries," Stites says. "They provide all hardwood material, custom sorted to CDS's specifications."

Manufacturing flow

There are four Whirlwind cutoff saws at the start of the process. Two saws feed the cope and stick value streams and the others feed the other processes.

Cut pieces go through an Extrema ripsaw, are glued on a Newman RF gluer, and then glued panels are cut to width and end trimmed to square up and final size on a Rogers vertical panel saw. A DMC planer is the next step, and then pieces go to one of two assembly cells, with a number of SCMI shapers and sanders.

"We process the panel, shape it, sand it and get it ready to go into the frame of the door. Frame parts are also cut on a Whirlwind cutoff saw with TigerStop and machined just before assembly," Stites says.

Doors then go to a DMC Unisand 2000 widebelt sander, then back to the assembly cell where the edges are sanded by hand. That cell owns the entire job, Stites says, to create ownership by employees. Then doors go to a DMC Unisand 2000 orbital sander.

Takt target time is 80 seconds per door for each of the assembly cells, so each person is assigned 80 seconds worth of work.

"When demand slowed down, my advice was to keep people going at the same pace and shut down one cell on one shift, rather than varying the takt time to account for more or less work," Looper says.

Specialized cells

In the dovetail drawer department, the first to change to lean methods, drawer blanks are ripped on a saw, machined and boxes are assembled. Total production lead time is 3-1/2 minutes.

Most of CDS's door business is cope and stick construction, but about 10 percent of business is miter. The miter door cell features a Balestrini mortise and tenoner. In another area, mouldings are applied to the finished doors. Applied moulding doors account for about 10 percent of business and that is growing.

The finishing department is set up for a standard unit of processing time, combining doors, drawer boxes, drawer fronts and mouldings on the same cart. CDS uses Becker sealers, Becker conversion varnish, and a water-based no-wipe stain mixed in house to provide custom color matching. They are currently glazing by hand.

Foil doors, drawer fronts and components are made with an Shaw Almex Thermolaminator under the brand name ThermoLamRTF and are available in 30 colors. Also here is an Andi Exxact Plus router and spray booth where adhesive is applied. Foil accounts for about 8 percent of business.

Stites says he could never get lean going until he learned value stream mapping. He says there is 20 percent more efficiency that can be gained, Looper believes it is closer to 30 percent.

"The biggest part of the story is that lean has become a business model for us," Stites says. "It's allowed us to look at the market in a different fashion and to be able to bring superior value to the market because of the lean operation we're employing."

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About the author
Karl Forth

Karl D. Forth is online editor for CCI Media. He also writes news and feature stories in FDMC Magazine, in addition to newsletters and custom publishing projects. He is also involved in event organization, and compiles the annual FDM 300 list of industry leaders. He can be reached at [email protected].