Toyota Production System

The Toyota Production System (TPS) is the way Toyota organizes production: make only what the customer has ordered, at the moment it is needed, and stop as soon as a defect appears so it gets fixed at its source. Toyota built it from the late 1940s onward, largely under the engineer Taiichi Ohno. It is the origin of lean manufacturing. Where Taylorism handed the design of work to specialists, Toyota gives part of it back to operators.

Just-in-time and jidoka

The system rests on two pillars. With just-in-time, each step produces only what the next step asks for, in the quantity it needs. Kanban cards carry that request back up the line. Inventory stays low, which also brings problems to the surface instead of hiding them behind stock.

Jidoka, often translated as autonomation, means that a machine or an operator stops production as soon as something goes wrong. On Toyota's assembly lines, any worker can pull the andon cord to halt the line.

Waste and continuous improvement

Ohno sorted waste, or muda, into seven categories: overproduction, waiting, transport, over-processing, inventory, unnecessary motion and defects. Devices such as poka-yoke stop defects where they occur. Improvements, known as kaizen, come from the people doing the work, who propose and test changes at their own station. Toyota also runs several models on the same line and smooths its production schedule, so the flow stays steady when demand shifts.

Beyond the car industry

John Krafcik, then a researcher at MIT, coined the term lean production in a 1988 article. Hospitals, banks and software companies have since borrowed the principles of TPS. Kanban, for instance, became one of the agile methodologies.