This posting is a continuation of my series on how I first got started with the Theory of Constraints and the integration of TOC with Lean and Six Sgma.
As I held my breath, a team of experts checked and re-checked the control points on 10 different hardtops and to my jubilation every single measurement was conforming. So much so that the head of purchasing told me in his heavy German accent that his team had never encountered such “perfect” parts before on any audit. He then selected a hardtop and we had it mounted on his Z3. He instructed me to drive to the Interstate so that he could listen for air leaks between the hardtop and the mounting surface. We were traveling the speed limit (65 mph) and he instructed me to speed up to 70 mph. He said nothing as his ear was now almost touching the windshield carefully listening. He told me to increase my speed, but didn’t tell me how fast, so I floored it. At 95 mph he leaned over, smiled and told me I could slow down, but of course I didn’t. When we hit 110 mph, I could see distress in his eyes so I slowed down to the speed limit. As we pulled into the plant parking lot, he simply looked at me, pointed to the hardtop and said, “Great hardtop!” It was clear that we had passed his hearing test with flying colors.
Once back inside the plant, the head of worldwide purchasing wanted to mount a second hardtop, apparently to compare our paint job to his Z3’s paint job. We mounted the hardtop and he proceeded to walk around the vehicle several times, meticulously assessing our paint quality. With his hand stroking his chin, he said, “Mr. Sproull, we have a big problem!” I shuttered to imagine what was wrong with our paint job and he nervously replied, “There is nothing wrong with your paint job Mr. Sproull, but it doesn’t match our own vehicle.” I pressed him for more information and asked, “Do you mean the color doesn’t match?” He replied that it wasn’t a color issue, but rather the quality of the paint job. When I looked closely at the hardtop and his vehicle, it was clear that his vehicle's paint job had orange peel in it. I asked him facetiously if he wanted us to start adding orange peel to our hardtops, but he failed to see any humor in my comment. And with that, the audit was complete and we had passed with more flying colors! I don’t think I have ever been more proud of a workforce than I was for my team.
With the successful customer audit behind us, our next order of business was to develop an effective scheduling system that would guarantee on-time delivery to our customers, while at the same time prevent us from over-producing parts. In the past this plant had measured and reported efficiencies as one of the key performance metrics. We had learned from reading The Goal that this metric and other Cost Accounting based metrics were taking us in the wrong direction. When I had arrived at this plant, there was WIP stacked everywhere on both sides of our plant and as I looked into the reason why, it was clear that by using efficiency as our primary metric, we had over-produced on our non-constraint process steps. It was time to take a stand, so I instructed my folks to only measure and report efficiency at the constraint.
Although our team considered a variety of different scheduling systems, we finally decided to follow the lessons we had learned in The Goal and implement at least some form of Drum Buffer Rope (DBR). Drum-Buffer-Rope is TOC’s production application and is named after its 3 essential components; the drum or constraint or weakest link, the buffer or material release duration, and the rope or release timing mechanism. I can tell you that we really didn’t know what we were doing, but decided to push on with our implementation. We knew there would be mistakes made, but we would learn from them and modify our solution as necessary. We knew that our outcome would be a more robust and dependable scheduling process that would allow us to produce more, with less inventory and better on-time delivery, so we started our DBR effort.
To be continued........