The important and influential ideas of W. Edwards Deming include a System of Profound Knowledge, 14 Points for Management, and the 7 Deadly Diseases. While Deming was not an innovator of practical tools to implement Lean manufacturing, he was a thought leader and continues to influence those who champion Lean transformations.

Though lesser know, and possibly unfortunately titled, Deming also identified a so-called "Lesser Category of Obstacles." It seems arbitrary and subjectives to place these four as lesser evils than the aforementioned 25 (14 points + 7 diseases + 4 parts of the system). In my subjective experience, they are just as if not more important in a successful Lean transformation.

1. Neglect of long-range planning
Deming said "The most important things are unknown or unknowable" and this point was made again recently through deft use of statistics in a book called The Black Swan. Only the longest range planning will take into account the things that truly matter and allow you the possibility of considering that a comet-like event is due in your industry, any day now. This changes your Lean implementation focus from implementing tools to developing people, as people are flexible, and manufacturing systems are not.

2. Relying on technology to solve problems
It seems like every week there is a press release about a Lean manufacturing enabled / enabling technology solution. They may all be great products, but it would be advisable to spend those millions to have a solid people-based problem solving system in place before implementing technology solutions, Lean or not, as technology can create its own problems... which you better have a great problem solving system to deal with.

3. Seeking examples to follow rather than developing solutions
But aren't we supposed to copy Toyota? The best way to reconcile the seeming contradiction is to understand that we need to copy the thinking that led to the solutions, not the solutions themselves. How many times have we seen "flexible manufacturing" systems of various sorts, more based on tracing textbook cellular layouts than based on a deep understanding of how to design and run them? Too many. If you copy the thinking correctly, the solution may be the same. See the System of Profound Knowledge for details. Here's a thought: even Toyota copies Toyota.

4. Excuses such as "Our problems are different"
When have we heard this before..? Merely hours ago. When talking to a customer, it is just about guaranteed that we will hear this excuses. I'm guilty of it myself. It is far more difficult (Deming would say impossible) for someone within the system to see and understand it, in order to transform it. So "no excuses needed" is not only a good policy, it is a Lean mindset.

We are stumbling far more on these Lesser Category of Obstacles than we may think.