October 2005

Managing Quality -

Part III: Continuous Improvement

The road to a lean woodworking plant that produces quality products is paved with continuous improvements.

By Tom Dossenbach
It is not enough to simply correct a quality problem immediately so an order can be shipped on time. A thorough investigation must be done to get to the root cause of the error and eliminate it altogether.

Illustration by Chris Nititham

For the past two months I have dedicated this column to the subject of managing quality. In August I discussed the definition of quality as having little to do with the price of a product but everything to do with "meeting the customer's expectations." I also reviewed the need to define those expectations and educate your employees so they understand these requirements. Last month I covered the subject of preventing errors and defects as opposed to focusing on detecting non-conformance events, and stressed that prevention of defects was a better strategy than inspecting for defects.

This month I want to focus on prevention through positive change as the heart of a good quality management program. The type of change I refer to is one that will forever change the way you manufacture your wood products as well as permanently raise the level of quality throughout your company.

Remember the goal of good quality management is zero defects. The preferred way to achieve 100 percent defect prevention is through continuous education and training because well-prepared workers know how to make wood products that always conform to customer requirements.

Unfortunately, there is a learning curve during which time non-conformance issues will occur while you are training and improving your processes. While you certainly do not want errors to occur that cause non-conformance to customer requirements - you should welcome any occurrence as an opportunity to learn and to make a positive change to eliminate the root cause of that error from ever happening again. Put another way, no error or resulting defect should occur more than once. Thus, the question becomes: How do you prevent a non-conformance event from recurring?

ECR - Error Cause Removal

The typical woodworking plant experiences several quality problems each day. If you and others in your plant are like most, you are very busy and constantly have to make decisions on how to use your time most effectively. The critical question is, do you? Do you decide or do you let circumstances make the decisions for you?

When a production problem arises in a factory, something must be done immediately to restore production flow, otherwise throughput is reduced and productivity suffers. While it behooves you to fix the problem immediately so an order can be shipped on time, there is a huge difference between simply correcting a quality problem so production can temporarily resume and discovering the root cause of the error and eliminating it altogether.

There are two distinct steps that should occur in the process of addressing a quality problem. The first is restoring flow (RF) and the second is error cause removal (ECR).

I think we can all agree that it is urgent to restore production flow as soon as possible. Unfortunately, 80 percent of the time RF is the only action taken and ECR is forgotten as another production "crisis" arises and the prior problem is quickly forgotten. Does this sound familiar to you?

Let's consider the fictional Ajax Furniture Co. in Austin, TX, to see examples of RF and ECR in action. Glen is a machine operator working in the drawer cell. He uses an overhead router in the manufacture of drawer fronts. Suddenly, he notices that his most recent parts do not match specifications as they did just a few minutes before. Upon further investigation, he finds that for the past dozen or so pieces, the cut has gradually moved further and further from specifications and are now non-conforming. Glen stops the router and checks the set-up jig. He discovers that the hold-down bolt has loosened. He re-positions the jig and tightens the bolt to correct the problem.

Follow these eight steps to prevent the same error or defect from happening again:
  • Detect and report errors and defects so they can be evaluated.
  • Define and document the problem, not the symptom.
  • Implement a quick fix if necessary to restore flow.
  • Analyze the problem until you get to the root cause.
  • Identify potential solution(s) to the problem.
  • Determine the best solution that will prevent this from happening again.
  • Implement solution.
  • Measure and confirm success.

Glen is satisfied that he has restored flow and has solved the quality problem - the loose bolt. However, an hour later the same problem occurs. Glen calls Sue, the cell team leader, over to his workstation and explains the situation to her. She immediately notices that the threads on the bolt are partially stripped and radios the maintenance department to bring a new bolt to the drawer cell PDQ. Sure enough, maintenance verifies that the bolt is in need of replacement and makes the repair on the spot.

The moral of the story is when Glen first experienced this particular problem, he should have looked for the root cause of the slippage. If he had, he would have avoided a second work stoppage and additional spoiled parts. Sue, on the other hand, took the additional time to determine the real cause of the problem and thus eliminated future non-conformance occurrences of this type.

The Answer Is Blowing in the Wind

Meanwhile, in another part of the plant, Frank, the supervisor of the panel department, notices an edge-glued panel has a fine crack in a glue line. Upon further inspection, he finds several panels in the stack with the same problem. Frank's first instinct is to order someone to go through the panels and re-rip the bad glue lines and then re-glue the bad panels because the panels are badly needed to fill an order. However, Frank has read articles on ECR and decides it is imperative to find out what caused these panels to become rejects in the first place.

Frank breaks a couple of panels at the glue line and examines the edge surfaces. He notices that there is very little wood failure, but that there is a crystal-like appearance to the glue that is present on the edges of the glued pieces. After asking himself, "Why is this?" Frank goes to the clamp carrier to check the quality of the glue lines of pieces that have not been assembled into panels yet. He notes that the ripped edges look perfect. He then walks closer the clamp to watch the operators spread the glue, assemble the panels and clamp them. His mouth flies open as a blast of air hits him in the face.

It turns out a huge fan is blowing right on the glue operator and on the wood that has freshly applied glue waiting to be placed in the machine. He notices that it takes several minutes for the operators to remove a pallet of edge-glued panels from the clamping area and to start processing another stack. Meanwhile, the fan continues blowing on the newly glued pieces and a skim begins to form during the temporary stoppage. Frank confirms that the fan is causing premature drying of the glue whenever there is any delay in processing. In this case, the problem resulted in several defects or panels in non-conformance on each pallet.

Frank takes the time to explain the nature of the problem to all concerned. He orders that the fan be removed and issues a maintenance request to install an overhead fan that will not blow directly onto the glue spreader operation. He also assigns the operators the task of finding a way to eliminate downtime while removing pallets of glued panels.

As this example clearly shows, ECR is not rocket science. The secret lies in following the eight simple steps included in the box on p. 25.

Continuous Improvement

The two examples above show how attacking the root cause of quality problems can prevent reoccurrence and steadily improve the overall quality and productivity of a plant. Productivity increases when rework and production interruptions are avoided in the future.

This approach to quality management can be the catalyst of a continuous improvement program as all employees are trained to additionally apply ECR to any non-value-added activity. Thus, I encourage you to employ this strategy in your company. The benefits will include reduced costs, satisfied customers and happier employees who feel empowered to make a difference.

Not all ECR efforts will be as simple and straightforward as the examples cited here; some will even be simpler. The point is that quality must be managed in your company and this management must not be by inspection only or by just keeping statistics. Defect prevention is the key and occurs proactively when you look ahead for potential problems, and react immediately to errors as they occur with ECR. Doing this is required if you are to have a successful lean manufacturing culture in your company.

As I write this on a plane returning from Vietnam, I am reminded of how most exporters to the United States still only have a focus on restoring flow when it comes to quality management. I hope Wood & Wood Products' readers realize the importance of continuous improvement in quality management so you all can have a leg up on your low-wage competition.

Please, if you missed the first two parts of this series, I urge you to go back and read them.

Tom Dossenbach is managing director of Dossenbach Associates LLC, a Sanford, NC-based international consulting and research firm. Contact him at (919) 775-5017 or at www.dossenbach.com. The first and second installments of this 3-part series are also available.


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