I remember a project where I helped facilitate problem solving teams at a small manufacturing company. One team was working on coming up with new scheduling software to help them schedule samples. (They commonly had requests for samples of their product and when a sample order was put into the production process it often caused problems).They had trouble meeting both the sample required date and being on-time to their regular production schedule. They had framed the issue as one that required changes to their production scheduling software.
By now, you have probably already said to yourself that new software was not a problem but rather a solution. People often present their solution as the problem. For example, “the problem is our current software doesn’t allow us to properly schedule small sample runs.” I found the team in a conference room brainstorming ideas about how to better schedule samples. I asked them why their production process was not able to accommodate the interruption of a sample order. No answer. I asked what were the steps in the production process and where in that process did the sample order cause a problem. After some discussion it was clear that there were many differences in opinion. Finally, I asked.them why they were in a conference room arguing. I suggested we all go to the line and try to better understand what is really going on.
As we walked the line I had my notebook and pencil out. We walked each step and took note of the work-in-process inventory. I timed and recorded the cycle time of each process step. We asked the workers how long it took to change-over from one product to another. And we asked the workers about the kinds of problems they experienced when a sample order needed to be completed. It took us about 20 minutes. When we were done we had an old fashion process and material flow chart (today more commonly called a value stream map). In addition, our discussion with the workers pointed us to one step in the process that commonly got behind when sample orders were put into the process.
Together as a team we referenced the map to come to a common understanding of how the process really worked. Doing the math with the cycle times and change-over times we had on our map it was easy to see how a sample order that required extra time at one step of the process tended to starve the rest of the production line, causing regular production to fall behind. Again, standing right there on the production line we did the mathematical calculations and discovered that additional WIP at one process used as a buffer to the interruption caused by the sample order could keep the line running and on-schedule. The team decided to increase the WIP according to our calculations and run an experiment with some sample orders that afternoon to see if it worked.
As we were walking away from the line one of the members of the team told me, “It usually take us two days just to do a value stream map, but you just did one in 20 minutes.” I explained that the purpose of a value stream map is to create a common understanding of a process. My observation of the team’s discussion told me they didn’t have this common understanding. They were all arguing based on opinions. We needed to go see and to draw what we saw so everyone would understand the problem in the same way.
By the way, with a couple of check and adjust cycles they got the WIP inventory at the right level so that samples no longer caused a problem at a total cost of $0. The process of drawing the map also pointed out some equipment that was being underutilized that ended up giving them additional capacity at no added cost. This is the real impact of Lean, freeing up capacity for growth.
So, how are you doing value stream maps? Are you spending days, using fancy software to come up with pretty maps suitable for lamination? Are you worried about whether you have used the right symbols and recorded all the right information? Or, are you drawing simple representations of how the processes link to create value? Are you doing it as a team to create the common understanding that leads to agreement to implement a countermeasure as an experiment? And, are you doing it at the gemba by actual observation and in discussion with the people who do the work?
I encourage you to use the powerful tool of value stream mapping in quick and simple ways. With pencil and paper, work with your teams to collect just as much information as needed to better see and understand your process steps and how material and information flows through those processes. Grab your team, your pencil and pad, and go see to understand together.