{"id":"heijunka","model_id":"Heijunka","name":"Heijunka","summary":"Heijunka is the leveling of production type and quantity over a fixed period. It aims to meet customer demand while avoiding batching and reducing inventories, capital costs, manpower, and production lead time across the value stream. Quantity leveling can use a small finished-goods buffer to smooth daily demand, and type leveling uses repeating product sequences adjusted to customer orders.","study_notes":["Heijunka means roughly “levelization” in Japanese.","Quantity leveling example: weekly orders of 500 items with daily demand of 200, 100, 50, 100 and 50 can be leveled to 100 units per day with a small finished-goods buffer.","Type leveling example: weekly demand of five A, three B, two C and two D shirts can be sequenced A A B C D A A B C D A B instead of A A A A A B B B C C D D.","Heijunka differs from batch-and-queue scheduling, which uses long runs and avoids changeovers.","Batch production expands lead time, increases WIP inventories, hides defects, and creates uneven work.","An ABC Production Analysis is proposed to decide the production scheduling method when moving from batch-and-queue to heijunka.","Synonyms listed: Level Production; Production Smoothing.","The type-leveling sequence is adjusted periodically according to changing customer orders."],"safety_notes":["Unevenness in work creates strain, which corrodes safety and morale."],"sources":[{"url":"https://www.lean.org/lexicon-terms/heijunka/","title":"Heijunka — A Resource Guide | Lean Enterprise Institute","accessed":"2026-10-25"}],"verification":{"status":"source_checked","checked_at":"2026-10-25","values":1,"method":"llm_source_check"},"updated_at":"2026-10-25","type":"operational","spec":{"kind":"methodology","related":[]},"url":"https://machineschema.com/operational/heijunka","license":"https://creativecommons.org/licenses/by/4.0/"}