Lean Manufacturing Principles: Consistent is Better than Fast
Since the beginning of the Industrial Revolution, manufacturers have had a devotion to, not to say an obsession with, efficiency and speed. Everyone talks about efficiency, for example. I hear folks who couldn’t define efficiency on a dare speaking of its virtues. I hear references to the need for more efficiency in situations and circumstances where efficiency would be difficult and maybe impossible to quantify, e.g., physical therapy and product design. Even in those situations where efficiency as a concept and a metric makes sense, it’s used incorrectly as often as not. And all this is apart from the fact that much of what managers do to promote and improve efficiency actually hinders it. But that’s another discussion.
I’d rather that managers talked more about consistency and predictability. Let me give an example: let’s say it takes me an average five hours to complete a product changeover on a particular piece of equipment. The longest it ever takes me is five hours and 15 minutes and the quickest I ever get it done is four hours and 45 minutes. On the other hand, your average changeover time is four hours and sometimes you get it down in two hours but other times it can take you up to eight hours. Who would you rather have doing your changeovers? Who is going to make it easier to establish and meet a production schedule? I’m am, of course, even though I might not be as fast or as “efficient” in some cases.
We can play this same scenario out with any operating factor or metric: scrap, cycle times, errors, delays, uptime. My view is: better mediocre and consistent than highly variable.
Now I know what you’re thinking: “But shouldn’t we always be striving for excellence rather than just consistent mediocrity?” The answer is: “Of course!” But consistency is fundamental to excellence. Again, if I can be consistent at less than excellent performance, that’s a step forward from highly variable performance that is only occasionally excellent. Further, the steps I take to get more consistent will also help me achieve excellence. The path to eventual excellence goes right through consistency.