HEIJUNKA

The creation of a level schedule by sequencing orders in a repetitive pattern and smoothing day-to-day variations in total orders to correspond to longer-term demand. For example, if customers during a week order 200 of Product A, 200 of Product B, and 400 of Product C in batches of 200, 200, and 400 respectively, level scheduling would sequence these products to run in the progression A, C, B, C, A, C, B, C, A, C... . Similarly, if customer orders of 1,000 products per week arrive in batches of 200 products on day one, 400 on day two, zero on day three, 100 on day four, and 100 on day five, the level schedule would produce 100 per day, and in the sequence A, C, A, B... .

Some type of level scheduling is unavoidable at every producer, mass or Lean, unless the firm and all of its suppliers have infinite capacity and zero changeover times. However, Lean producers tend to create excess capacity over time as they free up resources and reduce changeover time. So the short-term discrepancy between the heijunka schedule and actual demand is steadily minimized and is aided by level selling.

Learn more about ERP for Lean, Systems and Resource Management, and Production and Materials Management.