Shingo’s ‘Know Why’ Hands-On Lean [the broken link was removed] by Bill Waddell. From Superfactory:
The essential element here is to be sure to identify every move the part makes from receipt to finish. How you represent it on the flow chart is not important, as long as each step is clearly identified and denoted whether it is value adding or not. It is also important that you develop the chart by personally walking the flow. Do not rely on a router or someone’s idea about how the process is supposed to flow.
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The primary message I am trying to send is that cycle time reduction efforts will generate almost immediate results if you use Shingo’s Why logic to deploy the right tool to the biggest problem first. The method and logic are simple. Every plant can have multiple improvement efforts in multiple processes going on simultaneously that all make sense.