Lean and Consistency
I was just reading an article on the Industry Week website, “Do’s and Don’t’s for a Lean Initiative Implementation”.
One of the “Don’t’s” is:
Don’t move forward with a lean strategy without first ensuring the processes being evaluated and optimized are consistent and predictable. Standardized tasks and processes are the foundation for continuous improvement and employee empowerment.
I agree with the sentiment of the statement. On the other hand, (and maybe this is just quibbling with wording), I view the “ensuring the processes being evaluated and optimized are consistent and predictable” as a central component of any lean implementation.
One of the “speeches” I usually pull out of my mental files for clients is around the issue of consistency and predictability and it focuses on changeover times (when it’s relevant to a particular client). A problem with changeover times at most manufacturers, of course, is that they take too long. But another, perhaps more important, problem is that they don’t always take too long.
When I ask operators, “How long does a changeover on that machine typically take?”, they’ll give me a ready answer that’s somewhere close to the modal changeover time (or maybe, the time of the most recent changeover). When I ask further, “What’s the fastest it ever gets done and what’s the longest it ever takes?”, I generally get a pretty wide range of time. So the issue isn’t so much that changeover times are too long. (If changeover times were always at the “longest it ever takes” time, the operation would at least be able to schedule better.) The important issue is that no one knows just how long a given changeover will take. That inability to predict, to say that “We’ll make that changeover in eight hours, no more and no less.” has a deleterious impact on scheduling, on inventory, on staffing, on shipping, even perhaps on purchasing.
We could say the same thing for variability in material, equipment and tooling availability, operator availability, operator performance, supplier lead times, and on and on.
So, back to the article…the way I’d say it is:
Do move forward with a lean strategy by first ensuring the processes being evaluated and optimized are consistent and predictable. Standardized tasks and processes are the foundation for continuous improvement and employee empowerment. [Words in italics are changed from the original article.]
Reducing and eliminating process variation isn’t a precursor to lean. It’s what lean is all about.