Is there a moment when you had your first breakthrough of clarity in your Lean journey? Have you ever had an “ah-ha” moment when things started making sense? I’m not sure if everyone has, but I did. When I started in manufacturing, my company was your typical batch build design with a push schedule and we had the attitude of “more inventory is better”. So when we started our one piece flow activity, it was a different experience, to say the least.
Our plant was designed so that there was a day of inventory between each department, which consisted of a tube cutting department, end forming, bending, brazing, leak test and final assembly department. This means that a product that has a daily demand of 1000 pieces would have about 5000 pieces of work in process (WIP). Our Lean journey got serious when we decided to take equipment out of each department and create a complete one piece continuous flow line. Because I was chosen to become the company’s first Lean coordinator, I was put in charge of the line before it was developed. We calculated the takt time, made cardboard representations of each equipment footprint and involved operators in helping develop the process. It was amazing and it was all done under the guidance of my Lean teacher, Mr. Ito. Eventually, the line was running. It had become the company’s model line. It was full of poka yoke’s, visual controls and other lean tools.
Then one day my “Ah-Ha” moment happened. We had a major malfunction on the line. A serious defect occurred at the very first operation and it didn’t get caught until the very last operation. I’d been in management for several years, and I knew how critical it was that I ensure the defect was contained, so I instinctively instructed for a full sort of all work in progress. What I saw really hit home. There were 8 people on the line and they all looked at the one part that they had at their station and inspected it for the defect. The sort was over in an instant! Previously, something of this magnitude would force us to scramble to find personnel to execute a very lengthy sort and we would be likely to scrap a lot of material that we would need to rebuild. We also run the risk of missing a defect or two due to human error in the sorting.
Not this time. What would have taken hours or perhaps days to sort before literally took a few seconds. The risk was almost nothing and the scrap damage was minimal. This also meant we only needed to make up a few pieces.
I really began to learn how to appreciate the advantages of single piece continuous flow production compared to batch building in island departments. That line taught me many great lessons, but this was a day that particularly meant a lot to me.
If any of you have ever had an experience that really had an impact on you, I’m sure everyone would love to hear about it. Feel free to share!