Heijunka

Heijunka is a traditional lean scheduling methodology for environments that contain a repetitive mix of products or a family of products. Heijunka is a kanban card post-box system that is usually at the pacemaker process. A Heijunka box provides process level scheduling/pacing, schedule visibility, and early problem highlighting.

Leveled production is customer order averaging so that small sequenced cycles produce the required volume and product mix. In a Heijunka box, customer monthly or weekly volume demands can be leveled into daily demands. Pull systems and Heijunka work well hand-in-hand.

Heijunka is the leveling of production by both volume and product mix. It does not build products according to the actual flow of customer orders, which varies with time, but takes the total volume of orders in a period and levels them out so the same amount and mix are being made each day.  The approach from the beginning is to keep batch sizes small and build what the customer (external or internal) wants.