I cannot think of day that has gone buy in the last ten years that I have not utilized it. It is from the book and handbook of Bill Jensen, Simplicity: The New Competitive Advantage in a World of More, Better, Faster and The Simplicity Survival Handbook: 32 Ways To Do Less And Accomplish More. I would recommend the handbook, but the original book can be purchased at a bargain price, so get both. My pinup on the wall looks something like this. 
If the Know, Feel, Do looks familiar to you, it is what Dan Pink discussed in his recent book, To Sell Is Human: The Surprising Truth About Moving Others. This is the part that I probably use more than any other tool. It is how I view conversations, creating scripts, and even writing blog posts. The Simplicity is not in completing the map. The Simplicity is in understanding the customer and delivering each and every time with relevant communication that attaches to the customer work (CLEAR), their needs (Behavioral) and with desired outcomes (Know, Feel, Do).
Recently, I have been discussing Training within Industry (TWI) and one of the “J” Programs is called Job Methods. When I review the Simplicity Map, it seems somewhat similar to the approach recommended in Job Methods. Enclosed is an outline of the Job Methods Card.
Any Thoughts?