The Toyota Way II: Controlled ExperimentsTo detail further how the Toyota Way (outlined in a previous post) actually works, I'll discuss today and tomorrow what Steven Spear and H. Kent Bowen discovered during four years of field research at over 40 Toyota manufacturing plants and a few competitors' plants.
Today I'll look at what Spear and Bowen have to say about how Toyota implements kaizen, aka continuous improvement. The basic principle is to combine learning how to work better with a plant's ongoing, day-to-day work processes.
In "Decoding the DNA of the Toyota Production System", published in the September-October 1999 issue of the Harvard Business Review, Spear and Bowen report that "the company's operations can be seen as a continuous series of controlled experiments." Workers are trained to conduct the experiments as part of the regular process of designing, producing, marketing, and distributing cars, and to respond immediately to any shortcomings they uncover.
This approach entails adherence to four tacit rules that Spear and Bowen eventually inferred from months of observation.
These rules guide the design, operation, and improvement of every activity, connection, and pathway for every product and service.An important outgrowth of these rules is that all employees can contribute intelligently to the work. No one is an unthinking cog; everyone is a trained problem-solver.
Rule 1: All work shall be highly specified as to content, sequence, timing, and outcome. [This is necessary so that workers can know immediately if what is actually happening diverges from what was specified.]
Rule 2: Every customer-supplier connection must be direct, and there must be an unambiguous yes-or-no way to send requests and receive responses.
Rule 3: The pathway for every product and service must be simple and direct.
Rule 4: Any improvement must be made in accordance with the scientific method, under the guidance of a teacher, at the lowest possible level in the organization.
All the rules require that activities, connections, and flow paths have built-in tests to signal problems automatically. [emphasis added]
The training comes at the hands of managers. Because so much of the workers' learning occurs on-the-job, the manager-teachers must be adept at facilitating learning-by-doing and at teaching how to use the scientific method as the basic problem-solving technique.