Build Quality In is a fundamental manufacturing philosophy at the heart of the TPS. It means that quality is not achieved through inspection or final testing, but must be embedded into every step of the production process.

The goal is to prevent defects from being created in the first place, rather than simply catching them later. Build Quality In is realized through mechanisms like Jidoka, where machines or workers stop the line immediately upon detecting an abnormality. By preventing defects from moving downstream, this concept minimizes waste (Muda) and drastically reduces the cost and time associated with rework, ensuring consistently high product integrity.

See also: Muri/Muda/Mura