Part 4 in our TIMWOODS Series
Shigeo Shingo, who is considered the world’s leading expert on manufacturing practices and the Toyota Production System, wrote “humans are animals that make mistakes.” But how often do we make mistakes in our lumber yards, millwork, and component operations? Trained military technicians make mistakes 20% of the time in simulated emergency situations. (Scary, isn’t it?) So is the solution to mistakes and defects getting rid of human operators and automating the whole process? No. Even if everything could be automated, we would still have imperfect raw material. We will always need to address the reality that “animals that make mistakes” are at the heart of our operations. We cannot eliminate all defects, but we can work to limit them.
Defects are what most people think of when you talk about waste, but these are only one small part of the eight wastes. Defects are mistakes that require additional time, resources, and money to fix. In a lumber yard, a defect might be moldy material that is passed on to a customer that you have to make a special trip to go back out and replace. In our component yards, it may be material with excessive wane or knots that passes through our saws and makes it to the assembly tables only to be rejected and stop production.
Recently I was in one of the many operations I work with each year and I saw both the good and bad of how defects get through our system. But let’s start with this philosophy right up front that should be non-negotiable for everyone:
- We do not accept bad work or material
- We do not do bad work
- We do not pass on bad work or material
These three principles serve as good best practice for any quality control program in any operation. Indeed, defects can be limited using best practices including standardized work plans, more stringent quality control at all levels, a full understanding of work requirements and customer needs, and simple job aids such as checklists and visuals.
Defects tend to be the result of:
- Poor quality control
- Poor documentation
- Poor work practices
- Misunderstanding of customer needs
- Poor design
- Poor repair
- Lack of standards
- Weak or missing processes
- Poor inventory control
- Undocumented design changes
One of the best practices I always teach at component operations is that you have three opportunities to catch defects before you assemble product: picking product, feeding a saw, and a sawyer. (Yes, this reduces to two opportunities with linear saws) That’s at least two or three sets of eyes on your raw material before it gets to the assemblers, and that provides opportunities to downfall material without stopping production.
We do not pass on bad work or material. This best practice was on display for me recently when I observed a sawyer and catcher working in tandem defecting parts (though not a high percentage) to ensure only good material reached the assembly tables. With no QC program in place yet, I asked the sawyer why he was doing this. His answer was that it would be what he would expect if he were at the table so he was not delayed any further.
Costs of Defects
Defects cost a lot more than what most managers think. It is not only the cost of the defect itself. Think about what has to happen: we have to rework the product or service, processes are interrupted, and, in many cases, manpower and machinery are stopped, and sometimes we have to go out to the site of the customer to rework material. We have already lost the time and capacity spent producing the part, then we have to reschedule and use more time and capacity to produce replacement(s). Most estimates calculate that the true cost of a defect is around ten times higher than the initial cost!
We do not do bad work. In contrast to the sawyer and catcher, a forklift operator pulling an order in the same customer’s lumber yard did not take steps to correct defects. When pulling loose material, they hit a bunk of material with their tines but still loaded the same material on that order. When I questioned him, he said the customer would probably accept it and, if not, they would be out to the site in a few days again. (Note: not to worry, we corrected the load before it left.)
Eliminating Defects
Best practices that you can implement in eliminating defects always start with your management team. You have to lead by example, set the standard, and show your team the importance of why we eliminate defects/waste in our operations. Quality Control programs are sometimes seen as necessary nuisances, but they are valuable lean management tools which can eliminate waste and defects in your yards and component plants.
Various QC programs exist for millwork operations and I have helped to write several for many clients. And for lumber yards, though there are no standardized QC programs, I always advocate for a program of back checks, material quality checks, etc. Again the focus should be on never allowing bad material to pass from our hands to our customers. For component operations (truss and wall panel) I always advise clients to use the SBCA QC programs. These programs have existed for more than 20 years and have been used by hundreds of operations across North America including the operations I owned. In fact, my father Don Hershey spent much time at Imperial Component writing some of the foundation of the original program along with several other Past Presidents and their operations. Today the SBCA QC program is even easier to use with the new data management program that SBCA staff has implemented. Many operations using the SBCA program have experienced cost savings due to reduced call backs and repairs, in some cases up to 65-75%. QC programs provide focus for each of our associates to recognize what we provide and produce for our customers.
QC Visual Aids
Defects, as evidenced above, come in many forms, so visual aids really help to identify what our management expectations are for each area of the operation. Particularly with Millennials and Generation Z, a visual aid may be all they are going to look at since reading could take ‘too much time.’ The more common types of visual aids are simple tools used to show such things as standards, examples of good and bad, and methods for inspection. These visual aids come in many different forms, and can be as creative as necessary to produce the desired results. To assist with visual inspection, mistake-proofing devices can be used to speed up the inspection process.
In many of our operations, sample boards showing bad, marginally bad, and good material may be used to help employees differentiate the various levels of parts being inspected. This can make it easier to identify and remove defects from the process. Other types of visual aids include photographs, drawings, diagrams, and samples of substitute parts. The concept behind these visual aids is to make it easier for employees to identify defects before value is added. Then add the simple “KISS” of reminding employees that passing bad material down the line is only going to cause additional downtime the further it gets in the process.
Lean Manufacturing and Quality Control really do go hand-in-hand. With attention from the entire team and a recognition that Quality Control is not just one individual’s responsibility in the operation, you will end up saving substantial time by eliminating defects and waste throughout the process. And remember, if we can be of assistance to you, if would be our pleasure to help you, give us a call!
Ben Hershey is the CEO of 4Ward Consulting Group, LLC, the leading provider of Lean Management and Manufacturing Consulting to the Structural Component and Lumber Industry. A Past President of SBCA, he has owned and managed several manufacturing and distribution companies and is Six Sigma Black Belt Certified. Ben has provided consulting to hundreds of Component Manufacturers, and is highly recommended throughout the industry. You can reach Ben at ben@4WardConsult.com or 623-512-6770.
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