Leveraging Variation

Working With The Grain, Not Against

Point 7: Institute leadership. The aim of supervision should be to help people and machines and gadgets to do a better job. Supervision of management is in need of overhaul, as well as supervision of production-workers…

A little later we’ll perform an experiment with red and white beads, trying to draw out random samples of fifty beads at a time, all white. The problem is that there are red beads and white ones in the bowl and when we pull out our day’s work, we have red beads along with white ones, sometimes three, sometimes thirteen, sometimes sixteen, sometimes nine. As long as those red beads are in the system, the people that work there will produce defectives.

See, the problem is that her seven people did not make the defectives; the system did it. She supposed that they could, by manipulating their fingers differently, eliminate defects. These seven workers did not make the defectives. They delivered them, yes, but they did not make them; the system made them.

Deming, W. Edwards; Orsini , Joyce (edited by); Deming Cahill, Diana (edited by). The Essential Deming: Leadership Principles from the Father of Quality (pp. 131-132). McGraw-Hill Education. Kindle Edition.

FOR TODAY’S POST, some lighter fare to think about over the weekend when not rushing about getting your last minute gift shopping and wrapping done. Back in early October I came across a video suggested to me by YouTube’s Algorithm(tm) that piqued my curiosity. It was created by a DIY carpenter (DIY Dave) who wanted to share what he’d learned about “finger joined lumber” - something he knew nothing about prior, but was intrinsically-motivated enough to want to explain to others.

For the uninitiated (which included me, at the time), pictured below is a finger-joined stud:

The carpenter wanted to know what these were and why he was seeing them in so many building applications. He had formulated a hypothesis or prediction that they were a way for builders to “cheap-out” or “cut corners” by stitching together scrap lumber, and this must be in some way inferior to having normal, long-length, non-finger jointed boards.

What he discovered in his investigation surprised him, and is I think a perfect example of Deming’s System of Profound Knowledge in action, specifically in the domains of Theory of Knowledge and Variation.

Theory of Knowledge: Prediction

As we’ve learned in prior posts, we gain knowledge by putting forward a theory and testing it when we apply it to a real-world situation. DIY Dave’s prediction was that finger-joined boards were a way for lumber producers to recoup/reuse scrap lumber and home builders to save money on framing. He had no hypothesis on whether this impacted framers who worked with the material, yet.

On closer examination of the joinery, he learned this method yielded strong bonds because the “fingers” provided a lot of surface area for glue adhesion, and has been used in a lot of other applications for this reason, such as door frames, moldings, and furniture.

He next learned that finger-joined boards were not, contrary to his prediction, made from scrap bits of lumber but by-products from cutting quality boards to standard lengths. Lumber mills finger join these odd-sized boards into longer lengths, thus solving a waste loss problem, but also creating a better product in the process. This is where things get interesting.

Theory of Variation

Recall from our July post on Variation how we learned Deming’s observation on the universality of this phenomena in our world. Variation is life, life is variation. He also repeated many times his belief in reduction of variation as key to producing higher quality products, and that all our efforts should be directed to understanding sources of variation in our systems, products, and services (which includes people!) in this regard. Variation underpins much of his theory of management.

However, what happens when the variation in our product is a consequence of Mother Nature? How do we manage this to our advantage? Pictured below are some framing boards at Home Depot that DIY Dave features in his video. See how they bow and warp uniformly with the grain? This is a natural consequence of the wood expanding and contracting as it is exposed repeated cycles of moisture and drying during production and storage.

Carpenters have long-known about this effect and have accumulated a number of compensating tricks of the trade to avoid uneven walls and consequently having nails or screws pop-out of drywall as the board dries out over time; but they are just that: compensation strategies. They’d much prefer to have straighter boards to begin with, as they’d spend less time correcting and more time framing and doing quality work.

DIY Dave discovered that lumber yards were not just haphazardly stitching left-over odd-length boards together, but carefully joining pieces with slightly-opposed grains to leverage the movement of each piece against its mate as they gain and lose moisture. To make this easier to see in the picture below, he added guidelines:

The resulting board is not only straighter than “virgin” boards, but resists the warping that would have to be compensated for with various carpentry tricks and techniques, which increases framing time, cost, and quality while still yielding problems for the homeowner down the road.

A framer with twenty years’ experience shared his enthusiastic support for these boards with DIY Dave in the comments to the video:

These studs are often way straighter and save many hours of fixing crappy warped lumber. They are just as strong in the right location and give the homeowners a better straighter wall.

Lessons From Working With the Grain

DIY Dave’s deceptively simple investigation yields a lot of lessons we can take-away when we view it through the lens of Deming’s System of Profound Knowledge:

It’s DIY Dave’s intrinsic motivation (Psychology) that prompted him to formulate a hypothesis about the finger-joined boards (Theory of Knowledge) that he then tested by going to a lumber mill to learn about how they are made. In the process, he disproves his hypothesis through the discovery that it isn’t a method of making cheaper-quality boards to cheat consumers, but a method of making a better board with off-sized discards that resists warping by aligning pieces with opposing grains (Variation). In turn, this helps framers build straighter walls more quickly and cost-effectively with less frustration, increasing their pride in workmanship (Psychology). All of this happens within the overlaps of many systems extending from Mother Nature to the homeowner (Appreciation for a System).

Perhaps the coolest a-ha! I had from DIY Dave’s video that motivated my interest to share it here was the way the lumber mills were reducing the natural variation in their product by finding a method to work with it - working with the grain of their inputs rather than against them. This presents a nice, nuanced take on Deming’s forthright direction to reduce variation to improve quality, which is often interpreted too literally as getting rid of the “red beads” in our processes to get us closer to our nominal target with minimal variance. The parable of the finger-joined boards demonstrates there is a way to “cut up” this variance to get even closer to the target than we’d have otherwise thought had we just accepted it as an unalterable fact of life.

Reflection Questions

Consider the story of DIY Dave’s discovery and the discussion above. What analogs to the warped and joined boards do you observe in your system? How could you leverage the naturally occurring variation in your products and services to reduce overall variation, as the lumber mill did? What innovations would be needed to make this happen? What would the resulting product look like? Would it seem to be a mere repurposing of “red beads”, or something more profound?