Value stream map
Definition
A value stream map (VSM) is a lean management technique that diagrams every step in a process from customer request to delivery, annotated with time data — process time, wait time, and inventory — to identify waste and opportunities for improvement.
Value stream mapping was developed at Toyota as part of the Toyota Production System and brought to a Western audience through Mike Rother and John Shook's 1998 book 'Learning to See.' The 'value stream' is every action — value-adding and non-value-adding — required to bring a product from raw material to customer.
A VSM has a distinctive structure. Across the top runs the information flow (orders, schedules, signals). Along the bottom runs the material or work flow (the actual steps). Between them is a timeline showing how long each step takes (process time) and how long work sits waiting between steps (wait time). The ratio of process time to total lead time is often shocking — in manufacturing and software development alike, work is actively being processed less than 10% of the time it spends in the system.
VSMs are drawn in two versions: current state (how the process actually works today) and future state (how it should work after improvement). The gap between them defines the improvement agenda.
In software and product contexts, VSM is applied to development workflows: from feature request to production deployment. Teams map where stories sit in queues, how long code reviews take, and where deployment bottlenecks exist. These sessions happen at whiteboards. BoardSnap AI reads the process steps, timing data, and waste annotations to produce a structured summary of the current or future state.
Examples
- Software delivery VSM: Feature request → Backlog grooming (2 days wait) → Development (3 days) → Code review (1 day wait) → QA (1 day) → Deploy (0.5 days) → 7.5 days total, 4.5 days process time
- Manufacturing VSM: Raw material → Machining → Inspection → Assembly → Shipping, with inventory triangles between each step showing WIP buildup
- Customer service VSM: Ticket submitted → Triage (4h wait) → Tier 1 support (30 min) → Escalation (2h wait) → Tier 2 resolution (1h) → Close
- Hospital VSM: Patient arrival → Registration → Triage → Waiting room → Doctor → Treatment → Discharge, with wait times at each queue
Related terms
Snap a value stream map. Ship its actions.
BoardSnap turns any whiteboard — including this one — into a summary and action plan.