What is the difference between incidental and waste?

Incidental work does not raise the value of the product but the process needs it today, such as walking for a tool. Waste consumes time without adding value and can be removed now, so classify by what the customer would pay for.

Should the shares add up to 100%?

No, whenever incidental time is present the two shares leave it out, so they sum to 100% only on a cycle with no incidental work. Watch the incidental band on its own until the process removes it.

How do I set takt for one station?

Use the demand it serves over the same period as the work time: shift minutes divided by units required. If several stations serve the line, every one compares against the same takt, not a local demand rate.

What does a negative gap to takt mean?

The station cycle runs longer than takt and cannot meet demand even with no waste at all. Redistribute elements, reduce the cycle, or add a parallel station before chasing smaller losses.

Lean Manufacturing & Operations calculator

Yamazumi Chart Balance Calculator

Break a station cycle into value-adding, incidental and waste time. You need the three times and the takt time the station is balanced to.

What this calculator does

Total station time split into value-adding and waste shares, checked against takt for the cycle the station must hold.

Formula used

Total station time = value-adding + incidental + waste
Value-adding share = value-adding ÷ total station time × 100
Waste share = waste ÷ total station time × 100
Gap to takt = takt time − total station time

Inputs explained

Value-Adding Work Time: Work the customer would pay for, from the time study.
Incidental Work Time: Necessary work that adds no customer value, from observation.
Waste Time: Time lost to waiting, walking and rework in the cycle.
Takt Time: Available time divided by demand for the station period.

How to use the result

Best suited to rebalancing a station over takt, showing operators where waste sits, sizing kaizen before a line redesign.
Incidental work is neither value-adding nor waste, so the two shares do not sum to 100. A single station cycle hides variation across shifts and operators.

Current U.S. benchmarks

U.S. manufacturing runs at 75.7% of capacity (Federal Reserve, Aug 2026). New factory orders are up 8.5% year over year (Census).

Common questions

What is the difference between incidental and waste? Incidental work does not raise the value of the product but the process needs it today, such as walking for a tool. Waste consumes time without adding value and can be removed now, so classify by what the customer would pay for.
Should the shares add up to 100%? No, whenever incidental time is present the two shares leave it out, so they sum to 100% only on a cycle with no incidental work. Watch the incidental band on its own until the process removes it.
How do I set takt for one station? Use the demand it serves over the same period as the work time: shift minutes divided by units required. If several stations serve the line, every one compares against the same takt, not a local demand rate.
What does a negative gap to takt mean? The station cycle runs longer than takt and cannot meet demand even with no waste at all. Redistribute elements, reduce the cycle, or add a parallel station before chasing smaller losses.

Last reviewed 2026-10-01.