Peer checking is a technique where two individuals work together to prevent errors before and during a specific action or task. Here are the key points about peer checking:

• It involves a performer (the person doing the task) and a peer checker (someone familiar with the task who observes the performer).
• The purpose is to prevent errors by the performer by having a second set of eyes verify the correct action is being taken.
• The performer and peer checker first agree on the intended action and component. Then, the performer performs the action while the peer observes to confirm it was done correctly.
• It augments self-checking by the performer but does not replace self-checking. Both individuals self-check in parallel.
• The peer checker provides a fresh perspective that is not trapped in the performer’s task mindset, allowing them to potentially identify hazards or consequences the performer may miss.
• It is recommended for critical, irreversible steps or error-likely situations where an extra verification can prevent mistakes.
• Peer checking should be used judiciously and not mandated for all actions, as overuse can make it become a mechanical process that loses effectiveness.
• It can also be used to evaluate potential fatigue or stress in a co-worker before starting a task.

Personally, I think we overcheck, and the whole process loses effectiveness. A big part of automation and computerized systems like an MES is removing the need for peer checking. But frankly, I’m pretty sure it will never go away.