Errors due to lack of standards - Some errors occur when there are not suitable instructions or work standards. Example: A measurement may be left to an individual�s discretion. Safeguards: Work standardization, work instructions.
Surprise errors - Errors sometimes occur when equipment runs differently than expected. Example: A Machine malfunction without warning. Safeguards: Total Productive Maintenance, work standardization.
Intentional errors - Some people make mistakes deliberately. Crimes and sabotage are examples. Safeguards: Fundamental education, discipline.
Mistakes happen for many reasons, but almost all can be prevented if we take time to identify when and why they happen and then take steps to prevent them by using Poka-Yoke methods with consideration to other available safeguards.