Level Loading

Level loading, also known as heijunka, is the practice of using demand estimates to establish an average production level.

By smoothing the demand, Lean companies can standardize their processes better, and can match their capacity to the current needs of the customer. Level loading on a mixed-model production line balances the mix of products in addition to the total demand by specifying a standard sequence of models. (i.e. ABABC ABABC)

Product planners should continually review both the quantity and product mix on a level loaded line to make sure that the numbers don’t get out of alignment with actual demand.

Keep in mind that level loading is a workaround. It either increases lead time for the customer who has to wait to get into the product mix, or it adds inventory when the mix doesn’t precisely match customer demand.