As most of you know, this blog is all about integrating the Theory of Constraints, Lean and Six Sigma. I’ve posted blogs about Lean and Six Sigma tools as well as those associated with TOC. In my blog posting today I want to relate a personal experience I had this past weekend and relate it to the basics of the Theory of Constraints.
It was a typical weekend for my wife and I in that we were doing the normal chores that most families do. You know, cleaning the house, yard work, etc. On Sunday my wife decided to do a couple loads of laundry like she does most weekends, so nothing out of the ordinary. I was in my office working and when the washer hit the rinse cycle, I heard this strange gurgling sound coming from our kitchen sink. When I got us to check on the noise in the kitchen, I noticed the right side of our kitchen sink filling up with water. Like most people, I’ve experienced this symptom before, so I immediately reached for the plunger and began working on the sink. The water receded and I declared victory….the plug must have moved out. But was I right?
The washer filled back up and continued on with the final rinse cycle, but this time I heard multiple gurgles coming from the kitchen sink and our downstairs bathroom. When I went into the bathroom, the tub had water in it and the commode water level was near the top. Oh boy, I thought, we have a major blockage, so my victory was very short lived. It was now late afternoon on Sunday, so I decided to wait until Monday morning to call a plumber. After all, there is a major premium for weekend plumbing work.
On Monday morning my wife made arrangements for a plumber to come to our house to help us. I hadn’t had a plumber to our house in years, so I was surprised at the technical tools our plumber had at his disposal. Ironically, the plumber we chose was the same plumber that had installed the plumbing in our neighborhood some 12-13 years earlier, so he no exactly where to look for the drain plug.
Being the TOC aficionado that I am, the five focusing steps automatically popped into my mind. As I thought about it, it became clear to me that our plumber unknowingly follows these same five steps. He questioned us about the symptoms we had seen and then removed the cap from the drain outside. Since it was full of water, his immediate conclusion was that the blockage was between our home and the street. He then insert his electrical device, referred to in plumbing language as a “snake”, and turned it on. It didn’t take long for him to remove the blockage and the water receded. I thought he was finished, but there was more.
The next thing he did was insert a sophisticated camera and was able to determine the source of the blockage. Of all things, a root from a nearby tree had somehow made its way into our piping system. He showed me the blockage his camera had observed and clearly there was a bundle of roots inside the pipe. My plumber had identified our plumbing system constraint, so step 1 of the 5 focusing steps was complete!
We then talked about what options we had to complete the fix. We had to decide between two options. It seems that this plumber had a cutting tool that could grind away the root bundle and free up the pathway for water to evacuate. He explained that this would provide temporary relief, but that, in time, the roots would grow back inside and the problem would repeat itself. This option would cost me about $700.
The other option was for him to dig up my front yard and replace the obvious broken or cracked pipe. He had another tool that was able to locate the exact location of the root bundle, including the depth. This option would cost around $2,500 to complete, so my wife and I had a decision to make. We had to decide which option we wanted to take, which we did. We opted for the $700 option, so step 2 was now complete, decide how to exploit the system constraint. I decided to be a satisficer rather than an optimizer. A satisficer does what is necessary to solve the problem at hand rather than choosing the perfect solution. The money difference helped with our decision.
The plumber called out another worker who brought a water jet cutting device and they removed the root bundle. Problem solved (again)! So using the first two steps of the 5 focusing steps we were able to arrive at a temporary solution. But the story continues.
My wife called her sister and explained what had happened to us and to her surprise, the exact same thing had happened to her sister several years ago. And then the real shocker came. Her sister explained that they too had chosen the same option we did and it worked just like ours did, but later on the problem came back with a vengeance. It seems as though this time it cost them $15,000! My wife panicked as I did and we ended up deciding to have the pipe replaced. After all, $3,200 is much cheaper than $15,000.
As I reflected on the events of this past weekend, another thought came to mind and this time it revolved around Six Sigma and root cause analysis. It seemed to me that I hadn’t really addressed the true root cause of this problem…..the nearby tree! So I have another decision to make in the near future….do I cut down that tree or not? If I do, I lose some of my property value, but if I don’t, this conceivably could happen all over again. I decided that I’ll put off that decision until later. It’s funny how the work I’ve been doing for so many years even applied to a plumbing problem!