What is Lean?

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I run into people on a fairly regular basis who want to know the definition of lean and what makes it different from the "normal" way businesses operate.  Because lean can be fairly complex and easy to misunderstand, I generally avoid any attempts to simplify it by describing it in a sentence or two.  There is such a common misconception about what lean is, though, that I finally felt compelled to come up with something.

Wikipedia defines lean as, "a production practice that considers the expenditure of resources for any goal other than the creation of value for the end customer to be wasteful, and thus a target for elimination."  Although I generally agree with this definition, there is not much in it that differentiates it from a traditional approach to business.  I've worked with some very non-lean thinking people over the years who would argue that they focus on their customers and continually work to eliminate waste from the company.  The difference here is in how they define waste and the steps they take to eliminate it (e.g., reducing costs by cutting rather than improving).  The point is that these leaders could argue that lean is not much different than what they already do.

The Definition

After a lot of thought and discussions on the subject, I've come to the conclusion that lean can be defined as:

A continual experiment to eliminate uncertainty from a business and achieve absolute perfection by leaving nothing to chance.

I believe this definition of lean incorporates the PDSA element that is absolutely necessary for learning and improvement.  By performing a process in a specific way (standardized work), we are predicting that a desired outcome will occur.  When it doesn't, the process needs to be adjusted (through kaizen).  We don't stop kaizen until the process is perfect because every problem identifies a weakness somewhere in our system that needs to be addressed.

A key difference between this definition and traditional thinking is the idea that the only acceptable result  is perfection.  The traditional approach to business does not usually consider perfection the goal.  People generally consider it impossible to achieve perfection and lower the bar by striving to be the best, among the best, or simply to meet a target.  While an organization with a lean mindset does strive to meet targets that take into account a given level of errors, defects, and variation, the people do not consider these things acceptable and will continue to drive improvement until things are perfect.

Although related to the drive for perfection, this definition also differs from traditional thinking by looking at all work as an experiment.  If you truly believe in continual improvement, you are always looking for problems.  You will standardize your processes  with the best knowledge you have at the time, but as soon as a problem occurs, you analyze the cause(s) of the problem and work to eliminate or reduce it.  And the changed process becomes the new standard.

Help or More Confusion?

I'm not sure that defining lean does much more than provide a starting point to the conversation about how a business can improve.  Although people generally want quick, easy-to-understand descriptions that will help them understand new methods, a definition that can be read in under 30 seconds will never provide enough understanding to intelligently accept or reject the concept. Improving understanding requires thought, discussion, and application to real situations - but if a one sentence definition starts someone thinking, than developing it was worth the effort.