Incorporating controlled error-proofing into the manufacturing process ensures the prevention and detection of errors, safeguarding product quality. Three main error prevention and detection methods are commonly employed:

1. Contact Method:

• Ensures error detection by verifying contact alignment, as seen in error-proof socket designs.

2. Quantitative Method:

• Detects errors when a fixed quantity is not reached, exemplified by part trace management to identify omissions.

3. Sequential Method:

• Involves working in a fixed order, detecting errors through interruptions. For instance, using sealed compartments for assembling screws in a designated order.

Principles of Error-Proof Design:

1. Root Cause Principle: Eliminate the cause of errors.
2. Insurance Principle: Require more than two actions for task completion.
3. Automatic Principle: Use various principles to limit actions and prevent errors.
4. Conformity Principle: Verify actions for conformity.
5. Sequence Principle: Arrange tasks in a numbered sequence to avoid errors.
6. Isolation Principle: Separate areas to protect critical parts.
7. Layer Principle: Distinguish different jobs to prevent mistakes.
8. Duplication Principle: Use duplication for repeated tasks.
9. Warning Principle: Display warning signals for abnormal phenomena.
10. Mitigation Principle: Reduce damage caused by errors.

Implementation Strategies:

1. Mould and Fixture Error Prevention.
2. Machinery and Equipment Error Prevention.
3. Device and Marking Error-Proofing.
4. Operating Conditions Error-Proofing.
5. Design Structure Error-Proofing.

Levels of Error Prevention:

1. Preventing errors at the source to avoid defects.
2. Immediate error detection after occurrence to prevent defects.
3. Immediate detection of defects after occurrence to minimize damage.

Advocacy: Emphasizing the first level of error prevention, which focuses on controlling errors at their source.