How much of my process time is actually worth paying for?
Tag observed process steps against the eight wastes and compute the value-add ratio.
Waste Walk · lean · White Belt · free, no account needed
Use this when
- You have observed a process end to end and timed each step
- Someone has proposed hiring more people to go faster
- You need to show where the time really goes
Waste Walk
sandboxClassify every step. Apply the customer test each time — would they pay for this? Effort and skill are never the test.
| Step | Min | Classification | Waste category |
|---|---|---|---|
| Arrive and join queue | 12 | ||
| Give name at desk | 1 | ||
| Wait for record retrieval | 8 | ||
| Confirm details | 3 | ||
| Wait for triage nurse | 17 | ||
| Triage assessment | 6 | ||
| Wait for room | 21 | ||
| Consultation | 14 |
Lead time
82 min
Value-add
0 min
Value-add ratio
0%
Waste
82 min
8 non-value-add steps have no waste category. Categorising them is what turns "this is waste" into a specific thing you can change.
How this is calculated
Value-add ratio = value-add time ÷ total lead time. The denominator is the whole clock, including every wait — not the time the team was busy. That distinction is what separates “how busy were we?” from “how much of the customer’s wait was worth it?”
- Value-add — The customer would pay for it, it changes the thing, and it is right first time.
- Business-necessary — The customer would not pay for it, but you cannot stop doing it.
- Waste — Everything else.
Source: Rother & Shook (1999), Learning to See; the eight wastes from Ohno (1988), Toyota Production System, Ch.3.
- Transport — moving the product
- Inventory — work sitting and waiting
- Motion — moving the person
- Waiting — work exists, nothing is happening to it
- Over-production — more, or sooner, than the next step needs
- Over-processing — beyond the customer requirement
- Defects — rework, correction or scrap
- Unused talent — the people doing the job were never asked
How this is calculated
Value-add ratio = sum(value-add time) / sum(total lead time). No inference; arithmetic on observed durations.
Source: Ohno, T. (1988), Toyota Production System, Ch. 3 — the seven wastes; the eighth (unused talent) is a later addition and is labelled as such in the tool.
Learn the method
- The 4% problem: how much of your process is actually worth paying forWhite Belt · 12 min · free