“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.”
Dave LaHote tells an interesting story, with good learning points for practitioners. Except that it is about process mapping on the shop floor, not “Value Stream Mapping” (VSM) as described in the Lean literature.
A VSM is supposed to map an order fulfillment process, following data from customer to supplier and materials from receipt to delivery. And, while quite detailed in terms of production control, it does not show process details at the machine or workstation level.
And it is not simple. It involves 25 different graphic symbols, some of which, like the zebra-patterned push arrows, take forever to draw by hand.