HEIJUNKA (Production Levelling)

Production levelling, also known as production smoothing, reduces Mura (unevenness) in production while also reducing Muda (waste).
It's a part of the lean process improvement approach that helps companies balance unpredictable customer demand trends and remove manufacturing waste by leveling the type and quantity of production output over a set periodoftime

Production Levelling uses a box similar to shown on the right. Pouches in the box have Kanban cards, each card representing a fixed quantity of parts.
Organizations that use a Heijunka schedule in their manufacturing processes will gain a variety of competitive advantages:
- Flexibility to produce exactly what the customer desires.
- Reduction in the inventory of unsold goods.
- Usage of labor and machinery in a balanced manner.
- Predictable demand on upstream processes and suppliers.

Consider a weekly demandas shown below
Parts are classified into three major categories:
- Runners: Parts for which the production runs every day.
- Repeaters: Parts for which the production runs are defined interval.
- Strangers: Parts either run with large intervals or without any defined interval and accommodated on need basis.