Frank comes in to run the line this morning, but thinks that the temperature should be higher than what Joe had previously been running at on the previous shift. So Frank makes an adjustment and raises the process temperature. Joe comes back in the next day and lowers it back down again, and both go about their work with little understanding of the impact they may have had on overall process performance. The end product all seems OK but is it really the same? Did the variation we just introduced to the process impact our final product? Will are customers notice, and will it cause an issue for them?
What about the bigger changes that are happening all the time? Are some of them changing the product in a way that might negatively impact our customer?
Controlling the process is critical to ensuring product consistency, and that the product is the same each and every time the customer uses it. Proper process controls are a key component to reducing variation, and although can seem like a daunting task, are really a matter of defining some key parameters and developing the rigour to stick to them.
By controlling critical process parameters, we are more capable to deal with the special causes that are a real cause for concern. Less variation means more consistent product and a better customer experience.