Also, using a process flow map, I have used the 8 Wastes with project team members as we collectively reviewed each process step and identified the wastes. To visually indicate the wastes on the process flow maps, I simply used another color. What is the right Lean way to visually point to the waste areas?
I don’t think there is a “right way” to designate waste. I have seen a flowchart entitled an opportunity flowchart where the swimlanes were “value-added” and “non-value added,” but honestly haven’t seen it utilized many times. Of course, in value stream mapping, bursts are commonly added to the map to denote improvement opportunities, such as waste.
Your suggestion of simply changing the color on those steps where waste has been identified is a good one and makes it easy for the team to see where improvement is possible.