Which Lean tool is designed to prevent human errors from causing defects?

Which Lean tool is designed to prevent human errors from causing defects?

• A. Heijunka
• B. Poka-yoke
• C. Muda
• D. Takt time

Answer: (B)

Poka-yoke is about making mistakes impossible or highly unlikely by designing processes and tools that prevent human error from turning into defects. It uses simple devices, checks, or setups that force the correct action or immediately halt a step if something is off. Think of a jig that only allows a part to be inserted in the right orientation, a go/no-go gauge, or sensors that stop the line if a component is missing. The goal is to build quality into the process at the source, so defects don’t pass to later stages. Leveling production to smooth workload helps reduce peaks and waste, but it’s not aimed at preventing human errors. The concept of waste (muda) highlights types of non-value-adding activity; it isn’t a specific error-prevention tool. Takt time sets the pace to meet demand, aligning production rate with customer needs rather than addressing how errors occur.

Poka-yoke is about making mistakes impossible or highly unlikely by designing processes and tools that prevent human error from turning into defects. It uses simple devices, checks, or setups that force the correct action or immediately halt a step if something is off. Think of a jig that only allows a part to be inserted in the right orientation, a go/no-go gauge, or sensors that stop the line if a component is missing. The goal is to build quality into the process at the source, so defects don’t pass to later stages.

Leveling production to smooth workload helps reduce peaks and waste, but it’s not aimed at preventing human errors. The concept of waste (muda) highlights types of non-value-adding activity; it isn’t a specific error-prevention tool. Takt time sets the pace to meet demand, aligning production rate with customer needs rather than addressing how errors occur.