How ZENDAIKYO calculates kosu
ZENDAIKYO's kosu are based on the Japanese Industrial Standard JIS Z8141:2001. For each part, we add up the main work time and the preparation time at the repair shop, and take into account work safety under laws such as those on work at height, and the difficulty of the job.
- 1Main work time – removing, installing and straightening parts.
- 2Preparation time – setup, masking and preparing tools and equipment.
- 3Safety & difficulty – work at height, heavy parts and other conditions typical of large vehicles.
Why heavy vehicles need their own standard
Trucks and buses come in many combinations of model, year and body. Their parts are large and heavy, and much of the work is done at height. That is why a standard separate from passenger cars is needed.
History of the reference books
The first edition of the reference book for medium and large vehicles was published in December 1979. It has been revised as new models appeared, and a small-truck edition followed in 1994. Since 2017 the Kosu Committee has calculated work hours using computers, and the books are now published by truck maker.