Value Stream Mapping
A practical technique for visualizing and improving flow.
1The Mapping Technique
Value Stream Mapping (VSM) is a technique for visualizing the flow of work and information required to deliver value. You draw the current state honestly, then design a better future state.
A basic value stream map includes:
Process boxes: Each step in the process (e.g., Development, Code Review, Testing, Deployment)
Inventory triangles: Work waiting between steps (e.g., 5 PRs waiting for review)
Information flow arrows: How work and information move
Timeline: Processing time vs. wait time at each step
Data boxes: Key metrics for each step (cycle time, first-pass yield, capacity)
The power of VSM is making the invisible visible. When you draw the map, waste that was hidden becomes obvious. "Wait, we really spend 3 days waiting for review?" "Wow, 40% of items fail QA and loop back?"
The Honesty Requirement
Map the actual process, not the documented process, and not the ideal process. If code reviews sometimes take a week, draw that. If testing is often skipped, draw that. Honest maps reveal; polished maps hide.
2Current State vs. Future State
VSM is done in two phases:
Current State Map: Draw how work actually flows today. Walk the Gemba (go to where work happens). Talk to people at each stage. Time the waits. Count the inventory. Don't judge yet—just observe and document.
The current state map usually shocks people. They didn't realize how long work waited. They didn't know how many items were stuck in queues. They didn't see the rework loops.
Future State Map: Design how work should flow. Eliminate unnecessary steps. Reduce batch sizes. Remove approval gates. Automate handoffs. Create flow.
The future state isn't fantasy—it's achievable improvement. Don't draw the perfect state that would require years of transformation. Draw the better state you could reach in weeks or months.
Between the two maps: an improvement plan. What specific changes will move you from current to future state? Who owns each change? What's the timeline?
3Walking the Gemba
"Gemba" is Japanese for "the real place." In Lean, going to the Gemba means going where work actually happens to observe it directly.
You cannot map a value stream from a conference room. You need to:
Watch work happen: Sit with developers as they work. Shadow QA engineers. Observe deployments.
Ask questions: What do you do next? What do you wait for? What slows you down? How do you know when to start?
Time the waits: When work enters a queue, note the time. When it leaves, note the time. Repeat for every stage.
Count the inventory: How many items are waiting at each stage right now?
Follow items through: Pick a specific item and trace its path from start to finish.
This takes time. It can't be rushed. And it must be done without judgment—you're observing, not critiquing.
Include Everyone
The people who do the work should create the map. Not managers guessing from reports. Include developers, QA, ops—everyone who touches the stream. They know where the waste hides.
The team instruments their workflow: ticket timestamps, PR timings, deploy logs. They reconstruct the value stream from data. It's not as rich as physical observation but captures the waits and queues accurately.
Management gathers in a room and draws the value stream from memory. They draw the ideal process. Nobody mentions the actual delays. The resulting map shows 3-day lead time. Reality is 3 weeks.
- Value Stream Mapping makes invisible flow problems visible
- Map current state honestly before designing future state
- Go to the Gemba—observe actual work, don't guess from reports
- Include the people who do the work in creating the map
- Focus on wait times and inventory—that's where most waste hides