Value Stream Mapping (VSM) is a Lean method for visualising how value flows through a process, from request to delivery. You draw every step, measure how long each takes, and mark whether the customer would pay for it. What you get back is a picture that makes waste hard to ignore.
Where it came from
VSM emerged from Toyota's production system in the 1980s under Taiichi Ohno and was popularised in the West by Rother and Shook's Learning to See (1998). Today it's used in manufacturing, healthcare, software delivery, government services, and knowledge work.
What it's for
- Making waste visible - especially wait time, which usually dominates lead time by 5-20x.
- Aligning a team on "what actually happens" (rarely what the process document says).
- Baselining before an improvement effort so you can prove impact after.
- Prioritising where to focus - the biggest queue, the worst bottleneck, the most manual step.
What it's not
VSM is not a documentation tool. If you draw a map and put it in a binder, you've wasted your time. The map is a means to a decision - about where to run a kaizen event, what to automate, or which handoff to eliminate.