What is value stream mapping?
A value stream map (VSM) is a Lean diagram showing the flow of materials and information needed to deliver a product or service. Each step records process time, waiting time, inventory and people, so you can see where value is added and where it isn't.
How to create a value stream map
- Choose one product family or service.
- Walk the process from the customer backwards, recording each step.
- For each step, note process time, waiting time, inventory and error rate.
- Draw the information flow — how orders and schedules move.
- Calculate total lead time vs total value-added time.
- Design a future-state map that removes the biggest delays.
- Turn the gap into an action plan with owners.
Example: purchase-to-pay
| Step | Work time | Waiting time |
|---|---|---|
| Request raised | 10 min | 2 days |
| Quotes collected | 1 hour | 3 days |
| Approval | 5 min | 4 days |
| PO issued | 15 min | — |
| Total | ≈1.5 hours | 9 days |
Common mistakes to avoid
- Mapping from memory in a meeting room instead of walking the process.
- Mapping everything at once instead of one value stream.
- Drawing the future state but never acting on it.
How DOOfy helps
A VSM is a snapshot; operations keep moving. AIMOS One records how long work actually waits at each step — approvals, stock, dispatch — so your value stream stays measured long after the workshop.
Frequently asked questions
What is the value-added ratio?
Value-added time divided by total lead time. In many processes it is below 10%, showing how much time is spent waiting.
What is the difference between VSM and a process map?
A process map shows the steps. A value stream map adds time, inventory and information flow, so you can see waste and lead time.