A few days ago my friend Jon Miller posted an interesting blog where the discussion was how to achieve zero defects. A few of my favorite bloggers, John Hunter and Pete Abilla, posted comments to Jon’s blog so I will not repeat what they already said. I do, by the way, agree with everything both of them said. Jon also had some excellent advice.
Personally, I think Jon may be a closet Six Sigma guru. He just doesn’t want to sound boastful (it’s all that Ohno reading I guess). Ha! Just playing with ya Jon.What I want to discuss tonight are some Six Sigma thoughts on how one may go about aiming for zero defects. Aiming for zero defects is an excellent attitude if you ask me. Is it achievable? Who knows and honestly I could care less. If I am ever faced with what to do when there are no more defects to battle I suppose I will deal with it then. But so far this has not been an issue.
Anyhow, if there is one fundamental equation that all of us – Lean and Six Sigma folks alike – must understand it’s the ever faithful: y = f(x)
This equation reads, “Y is a function of X.” It means Y, or our output, is a function of the X’s, or our inputs. This equation is the foundation for the standard Six Sigma DMAIC (define, measure, analyze, improve, control) roadmap. Without it we as Six Sigma practitioners would be lost.
The true power of Six Sigma, when used properly and for the right reasons, is when we are able to identify the critical X’s (inputs) in such a way that we can optimize them using tools like Design of Experiments and then monitor and control them using tools like control charts, control plans, and Poka-Yoke. “Wait a minute,” you say; “I thought Poka-Yoke was a Lean tool!” Read here for an explanation.
Jon’s blog started with this question from one of his many readers, “Is zero defects possible? If so, what are the steps. We are dealing with around 300 parameters each having minimum 25 to 30 parameters to be met. We find it difficult to maintain zero defect for all parameters. Any thoughts???”
In addition to the comments I have already made the best advice I can give this individual is to begin “funneling” through all these “parameters” as they call it. I imagine the term parameters may mean inputs (i.e. machine settings, raw material, etc.). If this is the case there is no better weapon available than DMAIC to help this company focus and refocus their efforts until they understand which of these 300 parameters are the most critical and need optimized and controlled.
What Jon’s reader may really be saying is that y = f(x1, x2, x3, x4, … x300). So you see this is a daunting task until we funnel these 300 X’s down to a more manageable level. DMAIC is designed for just this. I hope this reader is able to apply DMAIC. Otherwise the sledding will be tough.