4 Rules Embedded in the DNA of Toyota Production System

The 4 Rules of the Toyota Production System are Toyota’s DNA according to Steven Spencer and H. Kent Bowen. These authors believe that as hard as other companies try to reproduce Toyota’s Production System to achieve superior success they lack the key to producing Toyota’s DNA. Some companies have been able to replicate portions of the 4 Rules, but have failed to implement all of them.

The 4 Rules of the Toyota Production System are:
1. How People Work: All work should be specified, sequenced, timed, and output
2. How People Connect: Must have direct connections with suppliers and unambiguous yes-or-no way to send requests and receive responses
3. How the Production Line is Constructed: Must have simple and direct pathway for every product and service
4. How to Improve: Scientific Method must be used beginning at the lowest level of workers with the assistance of a teacher

The 4 Rules seem so simple and obvious that it makes you wonder how is it that no other companies have been able to execute the 4 Rules. Yet, as simple as Toyota’s DNA is to put on paper implementing it is not only the most important part of success but also the most difficult part.

One is quick to realize that there is no reason that companies cannot implement these 4 Rules. They are so basic that we have been doing them from the time we were children. To learn Rule 1, we all had toys that consisted of plastic or wood shapes that would only fit through its specified hole on a canister. For example, the rectangle block would only fit through the rectangular hole. As we repeated the actions, we learned how to reduce the time it took to get every shape into the appropriate hole. Rule 2 was taught on the first day of school when the teacher told us to raise our hand to go to the restroom. This was our first lesson in connecting with people in a “professional” manner. Mom teaches Rule 3, loud and clear as soon as possible. You are quickly taught that when you’re done with your toys, they have their own proper place to go. Stuffed animals go on the bed, books go on the bookshelf, and board games go in the closet on the shelf. The core of Rule 4, the Scientific Method is taught over and over in several different classes. Each time it begins to make a little more sense and you begin that it can be implied to anything. They do say that the greatest influence of your principles is your teachers and parents. Since some teachers and parents are more supportive and influential than others, some kids may never properly learn all of the 4 Rules. This supports the authors’ point that some companies have been able to implement some of the rules, but not all 4 Rules as a unit.

I fully agree with the authors that all other companies are missing that key to Toyota’s success, but I feel that they failed to include cultural effects. If there is one thing that I have learned in the past year as a lean implementer, it would be that cultural differences are forgotten too easily and quickly. That is if the cultural differences were even ever acknowledged and considered.

What are your thoughts?