Lean Lexicon
Lean started life as the Toyota Production System and much of its specialist vocabulary is Japanese. Some lean practitioners like to use the Japanese terms as they convey a precise meaning, while their English translations are open to misinterpretation as the terms are less specific. On the other hand, the English translations are more accessible and remove a potential barrier to learning represented by the Japanese jargon.
Sherpa Consulting has found that where a Japanese term translates as a paragraph, then it is sensible to use the Japanese word as shorthand for the concept, but where the word translates straightforwardly into English one may as well use the English.
The list below is all the terms we have found: if you find another please let us know and we will add it to the list.
| Andon | A signal, usually a lamp, that a machine or process has stopped itself because it has detected a fault. See Jidoka. |
| Asaichi | Morning market. A review in Gemba of the previous day’s quality issues and agreement of countermeasures to prevent their happening again today. |
| Chaku chaku | A machine which automatically ejects a completed part, sparing the operator the effort of removing it. |
| Gemba | The place where products or services are made or provided. This might be the factory floor, a hotel lobby, a supermarket or a sales office. It is a place which the value stream passes through and where value is added to the product or service. |
| Gembutsu | Something physical or tangible. This could be a broken-down machine, a defective product, returned goods or a complaining customer. Any investigation of a problem must involve examination of the gembutsu in gemba, the place where the fault occurred. |
| Hansei | Critical reflection to expose and understand any problems associated with a process or project and to develop countermeasures. |
| Heijunka | Workload levelling. |
| Hiyari | A warning report. This may be a ‘scare’ report notifying of unsafe conditions or occurrences which could lead to an accident in the workplace, or a quality report which warns of conditions which could lead to quality problems. |
| Hoshin kanri | Policy deployment. A process whereby high-level objectives set by senior management are expanded at each level to a set of subordinate objectives with links explicitly charted showing how these support the high-level objectives. |
| Hourensou | A reporting and communication system allowing senior managers to follow daily progress in a large project where it is impractical for them to attend personally. It may, for example, comprise daily email bullet-point reports from all managers involved in a project, circulated to all managers. |
| Jidoka | Autonomation – making a machine or process stop automatically when it detects a fault. The fault is signalled using an Andon. |
| Jishu kanri | Autonomous management groups. |
| Jishuken | Autonomous study groups formed by Toyota among suppliers to help them learn the Toyota Production System together, supported by experts from Toyota. |
| Kaikaku | Radical transformation. If a business is underperforming significantly, continuous improvement (kaizen) may not deliver improvements quickly enough. In these cases a radical redesign of operations is required. |
| Kaizen | Continuous improvement |
| Kamishibai | An auditing tool to check compliance with standardised work. A board has slots containing a card for each individual process in the overall production process. One process is audited each day and the card moved to an adjacent vacant slot to show it has been done. If changes are required or non-compliance discovered, the card is returned the wrong way round, highlighting the issue for attention. |
| Kanban | A signal used as part of a pull system to indicate that a process is ready for the next item from its upstream process. A kanban may be a card, a transport crate, a space on the floor, an electronic signal or any other appropriate form of communication. |
| Kata | A structured routine, especially a methodology for achieving continuous improvement. |
| Kentou | Study drawing. A phase in car design before the body design is fixed (clay model freeze) where a wide variety of technical options can be explored. |
| Kiken | Dangerous. |
| Kiken-yochi | Anticipating danger. |
| Kitanai | Dirty, e.g. unpleasant, dirty work |
| Kitsui | Stressful. |
| Kosu | Unit worker hours involved in the production of an item. |
| Minomi | Parts only – transferring parts between processes without any form of carrier or container. |
| Muda | Waste – activity not contributing added-value |
| Mura | Irregularity – variability in work |
| Muri | Strain – work which is physically more difficult than it needs to be. |
| Nemawashi | Making decisions slowly by consensus, thoroughly considering all options, before implementing rapidly. Ideas are circulated and buy-in achieved long before a formal decision is taken. |
| Obeya | A war-room approach to product development where all the senior members of the development team are gathered in a large room. The system enables faster decision making, improves communication, information gathering and team integration. Much use is made of visual management techniques. |
| Poka-yoke | Error proofing. Designing process stages in such a way that mistakes are impossible, unlikely or easily detected. |
| Ringi sho | A proposal being circulated for consensus. |
| Sarashi-kubi | Another word for gembutsu. It dates from mediaeval times and means the severed head of a criminal displayed in a village square. Evidence of a problem. |
| Sensei | Teacher. A Sensei’s job is to train and encourage the students, but not to do the work themselves. |
| Seiketsu | Systematize or standardise – see 5S |
| Seiri | Sort – see 5S |
| Seiso | Scrub, sweep or shine – see 5S |
| Seiton | Straighten, simplify or set in order– see 5S |
| Shitsuke | Self-discipline or sustain – see 5S |
| Takt | From the German for musical time or metre. The rate at which a plant must operate to produce the demanded output. |
| Yamazumi | A chart representing data as a stacked column |
| Yoshi | Explicit statement by an operator that a part has been checked for conformance to specification. |