In 30 seconds
- Smooths out peaks and troughs in work.
- A pillar of the Toyota Production System.
- In software: steady flow over big batches.
The idea
Heijunka means levelling. Instead of producing in big batches with idle periods between, lean factories mix and spread work evenly. Uneven workload (mura) causes overburden (muri) and waste (muda).
In software teams
- Keep a steady mix of features, bugs and improvements each sprint
- Avoid big-bang releases followed by quiet periods
- Use WIP limits and classes of service to smooth flow
Benefits
Predictable flow makes forecasting easier, reduces burnout from crunch periods and supports a sustainable pace.
Myth vs reality
Myth · Heijunka means doing the same work every day.
Reality · It means a steady, balanced mix.
Myth · It only applies to factories.
Reality · Knowledge work benefits from levelled flow too.
Myth · Big batches are more efficient.
Reality · They create waiting and uneven load.
FAQ
What's a heijunka box?
A board used in factories to schedule a levelled mix of work.
What are mura and muri?
Mura is unevenness; muri is overburden.
How do we level urgent work?
Reserve capacity or an expedite lane.