What is poka-yoke and how is it used in automotive assembly?

Poka-yoke (mistake-proofing) is designing processes and equipment to prevent errors or make them immediately obvious. In automotive assembly: Physical guides ensure parts can only be installed correctly; sensors verify correct parts before installation; fixtures only accept proper orientation; color coding differentiates similar parts; sequence interlocks prevent skipping steps; torque monitoring confirms proper fastening. Examples include asymmetric connectors, part presence detection, barcode verification, and vision-guided assembly. Poka-yoke reduces defects at source, eliminates reliance on inspection to catch errors, and is a fundamental quality principle.