In plain sight

It’s been more than a decade ago since my mentor helped me interpret a control chart that made little sense to me:

"Bruno, you see these sudden gaps here? Yes, right here, where the line suddenly cuts off. And do you see how the same pattern is repeated every few hours? There are two probable causes for that."

"First, the blade is getting dull, but the operator replaces it too late. It could be due to improper training, an attempt to save on the cost, or catalogue having inappropriate information."

"Second, another cause might be job handover. Perhaps the operators switch tasks with each other and just follow the time sheets instead of checking the control charts. They probably just check the reading on the machine, but that only provides the current measure, without history."

"Either way, you must go there and see for yourself."

I rushed back to the manufacturing hall inspired to inquire.

In doing so I learned several very important lessons:

  • Those who seek useful data will often find it available in plain sight.
  • Observing and validating the data is easier than we might think.
  • Information revealed by the data might not be a pleasant one.
  • Inquire mindfully, and ask to learn, not to accuse.

My mentor was right—it turned out to be a mix of the blade getting worn and operator simply monitoring the current value. There was no malicious intent, just a simple oversight.

Pay attention to the data around you. Take care to interpret it and question what it tells you. You might be surprised with what you find.