These are two basic paths that we could assume in our path to perfection. You can look at the fact that people will always make mistakes and therefore we must accept defects. We set up final inspection or checklist or just wait and see if the customer notices it. Or we can take the attitude that all mistakes can be eliminated by proper training and prevention. I prefer the latter.
Mistakes happen for many reasons, but almost all can be prevented if we take the time to identify when and why they happen. Let’s take the time to define some terms before we start. A mini-project charter per say. Mistakes(errors) are any non-conformity(deviation) passed to the next stage or worse yet, does not meet the customers expectation. A defect is the result of these mistakes.
Many companies will wait for the final product to sample for mistakes and a certain percentage of rejects is acceptable. Other will do 100% inspection. But from a marketing standpoint, use direct mail as an example, how do you do that? The production of the direct mail piece itself may be measurable but the can you Poka-yoke the response? What response rate is acceptable or what you would call defective or broken? We will tackle this conversation in future posts but for now, let’s find out some suggestions on how to error proof a process.
The basic functions of Poka-yoke control are stop doing it(shutdown), control(make adjustments) and warning(red flags occurring). Maybe, more important, is the two terms, prediction and recognition. Prediction states that something is about to occur and recognition is something has occurred. The closer the source to the mistake that it is discovered the less costly is the problem. The whole point of Poka-yoke and as you instill the process detection, this will drive better feedback which generates the proper actions. This is a continuous process that once installed continues on and on.