Departments
Intermediate Japanese - Free Online Course
Heijunka
平準化
The Toyota Production System (TPS) requires just-in-time (JIT) production. This means aligning production volumes to customer demand. However, every industry experiences fluctuations in customer demand.
A manufacturer of lawn mowers, for example, will sell more units in May than in November. This is an extreme example, of course; but fluctuations in demand also affect the consumer electronics, automotive, and machine tool industries.
If production schedules were aligned exactly to the peaks and valleys in consumer demand, then the result would be a strain on company resources when customer demand is at a high point, and idle resources when demand is at a low point.
The solution is to blend, or “levelize” the production schedule to account for these inevitable fluctuations in the volume of products sold. In other words, production volumes are “smoothed” over time, to account for the peaks and valleys. This averaging enables the company to maintain the minimum number of resources throughout the year.
Heijunka is a core concept within the Toyota Production System, and the word is commonly heard in Japanese industrial circles. The principle of heijunka has also been adopted by non-Japanese companies that use just-in-time production methods.