Spear and Bowen (1999) explain how TPS creates a community of scientists as the system enables establishing sets of hypotheses when defining specifications and then testing them. The system drives people at all levels (shop floor workers, team leaders, managers, etc) to get involved in experiments that are recognised as the drivers of organisation learning. Toyota sets up all its operations as experiments, and follows four rules to do that. (Spear & Bowen, 1999)
The first rule is how people work. People carrying out work should know exactly what the work involves in specific (content, sequence, timing, and outcome). As an example, Toyota mark the floor length for each work area in tenths to make problem detection easier. For each tenth there are a set of activities required. The worker understands the sequence of activities and when they need to be finished by. If the worker takes longer on an activity and passes the specified tenth for it, the worker and the team leader know that he has fallen behind. (Spear & Bowen, 1999)
The second rule is how people connect. For each specific good or service, a clear supplier-customer relationship is created. This leads to a definite decision on who provides what to whom and when. A direct connection must be established between each supplier-customer with a clear yes/no approach to sending requests and receiving responses. (Spear & Bowen, 1999)
The third rule is how the production line is constructed. Every product and service at Toyota has a simple and specific path which it flows through when setting up production lines. The third rule aims to make goods and services flow to a specific person or machine rather than to the next available person or machine. As an example, a worker on the line requires help, the help will come from a single specific supplier. If the specific supplier cannot provide the help, he/she in turn has a specific helper. In some cases pathways for assistance can reach four or five individuals long, linking the shop floor worker to the plant manager.
The fourth rule is how to improve. Under the fourth rule, Toyota demands that any improvement follows the scientific method, a teacher’s guidance, and at the lowest possible organisational level. Toyota management find it is important to understand how the changes are made, as well as, what changes are made. (Spear & Bowen, 1999)