"To be simple is to be Great." — Ralph Waldo Emerson
Simplicity is the key to effective continuous improvement. Simplicity is the state or quality of being simple. Simplicity is not simple. If it were otherwise, it would not be the subject of discussion. Simplicity would be what is taken for granted.
According to Occam's razor, all other things being equal, the simplest theory is the most likely to be true. A simple solution always takes less time to finish than a complex one. So always do the simplest thing that could possibly work next. If you find something that is complex replace it with something simple. It's always faster and cheaper to replace complexity now, before you waste a lot more time on it.
In my experience with problem solving in a Lean environment it is often those simple creative solutions at the source of the problem by those who do the work that are the most effective. Lean leaders understand this well and work to create a culture that fosters and develops the use of this ingenuity.
If your process isn’t simple, it’s going to be very expensive, not very usable, and probably not sustainable – put simply, it will fail. Whether evaluating new processes, or determining which ones to re-engineer or discard, make simplicity a key consideration. Remember this – usability drives adoptability, and simplicity is the main determinant of usability.
I think it was Leonardo da Vinci that said it best "simplicity is the ultimate sophistication."