Aiki (martial arts principle) and its practice is often kept within a particular individual or two from a family/school lineage. Culturally, and due to certain necessities of the time period, the aiki knowledge was usually a very well guarded secret and rarely disclosed. The oldest book to have historically discuss aiki was the 1899 Budo Hiketsu-Aiki no Jutsu. On the subject of aiki it was written: The Textbook of Jujutsu (Jujutsu Kyoju-sho Ryu no Maki) from 1913 wrote: Aiki (martial arts principle) Aiki from a Japanese budo term, at its most basic is a principle that allows a conditioned practitioner to negate or redirect
Muda (Japanese term) Muda (Japanese term) From an end-customer's point of view, value-added work is any activity that produces goods or provides a service for which a customer is willing to pay; "muda" is any constraint or impediment that causes waste to occur. There are two types of muda: One of the key steps in lean process and TPS is to identify which activities add value and which do not, then to progressively work to improve or eliminate them. Taiichi Ohno, "father" of the Toyota Production System, originally identified seven forms of "muda" or waste: Later, an eighth waste, unused skills, was added.