Hansei is a Japanese word meaning "reflection" as in reflecting on ideas or experiences in order to learn from successes or failures to improve oneself in the future. It is a key step in kaizen, both personal improvement and for process improvement activity in business.

Taiichi Ohno liked to say "Check is hansei". The "check" step of PDCA (Plan, Do, Check, Act) is an opportunity to reflect and learn before the Act / Adjust step in the PDCA cycle.

The quote of the day is attributed to Confucius, that people come to wisdom in three ways:

"First, by reflection, which is noblest; second, by imitation, which is easiest; and third by experience, which is the bitterest."

"Experience is the best teacher" as the saying goes, but the superior student combines imitation and experience with hansei. Experience without hansei can result in the "bitter" repetition of the same lesson.