• Bring your stopwatch and do not rely on standard times or infor- mation that you do not personally obtain. Numbers in a file rarely reflect current reality. File data may reflect times when everything was running well, for example the first-time-this-year three-minute- die-change, or the once-since-the-plant-opened week when no expediting was necessary. Your ability to envision a future state depends upon personally going to where the action is and under- standing and timing what is happening. (Possible exceptions to this rule are data on machine uptime, scrap/rework rates, and changeover times
• Map the whole value stream yourself, even if several people are involved. Understanding the whole flow is what value stream mapping is about. If different people map different segments, then no one will understand the whole.
• Always draw by hand in pencil. Begin your rough sketch right on the shop floor as you conduct your current-state analysis, and clean it up later again by hand and in pencil. Resist the temptation to use a computer