AiVibeIndustry 4.0 & Manufacturing Operations
Heijunka (Production Levelling)
Heijunka is the lean practice of levelling the volume and mix of production over time, so that a process makes a steady, repeating pattern of products instead of large batches, smoothing demand on people, equipment and suppliers.
Customer orders often arrive unevenly, and producing them as they arrive, or in large batches of one product, creates peaks and troughs throughout the value stream. Heijunka levels volume, by producing to average demand rather than chasing daily fluctuations, and mix, by interleaving products in a short repeating sequence. Rather than making all of product A on Monday and all of product B on Tuesday, a levelled schedule produces a fixed pattern of A and B throughout each day. A heijunka box is a visual scheduling tool that releases kanban at fixed intervals according to this pattern.
Heijunka is part of the foundation of the Toyota Production System. It allows smaller and more stable supermarkets, steadier workloads, more predictable staffing and less strain on upstream processes and suppliers, which makes pull systems practical. It is used in assembly, packaging and other operations producing many variants.
Levelling the mix requires short changeovers, because frequent product switches would otherwise consume capacity, so SMED usually precedes or accompanies heijunka. Some finished goods inventory is held to absorb demand variation while production stays level. The pitch, the interval at which work is released, is commonly calculated as takt time multiplied by the pack-out quantity.
Key points
- Levels both the volume and the mix of production over time.
- Replaces large batches with a short, repeating product sequence.
- Uses tools such as the heijunka box to release work at a fixed pitch.
- Depends on quick changeovers and a small buffer of finished goods.
Where AiVibe comes in
AiVibe designs and manufactures the AiAmbA AI Factory as the OEM: edge devices plus AI agents that let people talk to PLC, CNC and robot controllers in plain language. Existing lines are retrofitted with edge devices, and a trained operator confirms every change an agent proposes.
Explore AiVibe’s work in Industry 4.0 & Manufacturing Operations →