If someone walked up to your this morning at the coffee machine and asked you, “is process mapping a Lean or Six Sigma tool?” what would you say? This may seem like a trivial question but I dare say it is not.
Poka-Yoke is a Six Sigma Tool?
I remember reading Michael Georges’ book “Lean Six Sigma” and being taken aback a bit when he said Poka-Yoke was a Six Sigma tool. I thought, “Huh, are you crazy man?” Then I stopped for a second and realized I had first learned about Poka-Yoke in a Six Sigma training class many moons ago. So is Michael George, arguably one of the leading Lean Six Sigma experts in the world, wrong?
This gets right to the point of this blog which is which tool bag do certain tools belong? Let us begin with Process Mapping.
Types of Process Maps
Most of us have drawn up process maps. My favorites are the ones drawn up over lunch on a napkin. There are many different kinds of process maps such as:
- Detailed Process Maps
- Swim Lane
- Brown Paper
- Value Stream Maps
Each of these process maps help us in different ways and at varying degrees of detail but they all have one thing in common – they help us better understand how something works.
Both Lean and Six Sigma rely upon this basic understanding in order to get on with more advanced things like deciding if a step is muda (Lean approach) or determining which inputs are controllable, noise, or SOP (Six Sigma approach).
Value Stream Maps
What about Value Stream Maps, also referred to as ‘Material and Information Flow Maps’ by Toyota? Surely this is a Lean tool, right? I mean Toyota invented it! Well, out of respect for Toyota and the sensei that first drew them I would say that VSM’s officially belong in the Lean tool kit. But it doesn’t mean a Six Sigma practitioner cannot use them!
Process Maps Unite!
For example, a favorite trick of mine is to start with a SIPOC to get a better understanding of the process and who should be on my team (I use the supplier and customer columns and pick team members accordingly). I then usually move to a VSM where I “learn to see” the process. Next, depending on the situation I may decide to drill into a process step with a swim lane process map in order to really understand this process step. Now I am in position to decide if my problem is more of defects/variation (Six Sigma approach) or waste/speed (Lean approach). But you see I don’t discriminate and I use all the tools I have at my disposal in the beginning of any improvement initiative.
So, to answer my own question of whether of a process map is a Lean or Six Sigma tool I will respond with the obvious answer – yes!