Gidoka glossary
Kaizen and lean thinking come with a vocabulary of their own, much of it Japanese and much of it born on Toyota's shop floors. This glossary explains the core terms in plain English, from PDCA and gemba to takt time and A3 reports, so you can apply them at work or at home. Where an idea has a known origin, we note who developed or popularized it.
- 5 Whys
- The practice of asking “why?” repeatedly when a problem occurs, to get past the obvious symptom to the root cause. Taiichi Ohno illustrated it with a stopped machine traced back through a blown fuse and a worn pump to a missing strainer; the exact number five is not the point.
- Related:Root causeCountermeasureFishbone diagram
- 5S
- A workplace-organization method named for five Japanese words: seiri (sort out what isn't needed), seiton (set what remains in order), seiso (shine, or clean), seiketsu (standardize), and shitsuke (sustain). Its purpose is to make abnormalities visible and support improvement, not just to tidy up, and the same steps apply to a garage, kitchen, or computer desktop.
- Related:Red taggingVisual managementPoint-of-use storage
- A3 report
- A Toyota practice of putting a problem, its analysis, proposed countermeasures, and an action plan on a single large sheet of paper, often with simple graphics. An A3 sheet is 297 by 420 millimeters, close to US 11-by-17-inch tabloid paper, and the report doubles as a coaching conversation between a manager and the author.
- Related:CountermeasurePDCA (Plan-Do-Check-Act)Hoshin kanri
- Andon
- A visual signal, often an overhead board or light, that shows the status of operations at a glance and flags abnormalities. At Toyota, it lights up when equipment stops or when a worker pulls a stop cord to call for help. The word is Japanese for “lamp.”
- Related:JidokaVisual management
- Baseline
- The measured starting performance of a process, used as the reference point for judging whether a change is really an improvement. In lean practice, standardized work serves as the baseline, and PDCA targets are set against it.
- Related:Standardized workPDSA (Plan-Do-Study-Act)Target condition
- Basic stability
- A process condition in which people, machines, materials, and methods are reliably capable and available. Without it, improvements either fail to take hold or quickly fade; Taiichi Ohno's line “There can be no kaizen without a standard” points the same direction.
- Related:Standardized workKaizenBaseline
- Continuous flow
- Making and moving one item at a time, or a small consistent batch, through a series of steps as continuously as possible, with each step making only what the next step requests. It is also called one-piece flow or “make one, move one.”
- Related:Work-in-process (WIP)Lead timeJust-in-time (JIT)
- Continuous improvement
- An ongoing effort to improve processes, products, or services through many small changes rather than occasional overhauls. In lean organizations it is often used as an English synonym for kaizen, and it relies on frontline people spotting and fixing problems.
- Related:KaizenPDSA (Plan-Do-Study-Act)Standardized work
- Countermeasure
- An action taken to address the cause of a problem, which is tried and checked against results rather than assumed to work. A3 reports list possible countermeasures, choose the best, and record the evidence that the issue has actually been addressed.
- Related:A3 reportRoot causePDSA (Plan-Do-Study-Act)
- Cycle time
- How long it actually takes to complete a part or process, measured by observation. Comparing cycle time with takt time shows whether a step can keep up with demand.
- Related:Takt timeLead time
- Deming's 14 Points
- Fourteen principles for management that W. Edwards Deming first presented in his book Out of the Crisis. They include ceasing dependence on inspection to achieve quality, improving the system “constantly and forever,” driving out fear, and removing barriers to pride of workmanship.
- Related:System of Profound KnowledgePDSA (Plan-Do-Study-Act)Continuous improvement
- Fishbone diagram
- A cause-and-effect chart, named for its shape, that lists possible causes of a problem in categories such as people, methods, materials, equipment, and environment. It is also called an Ishikawa diagram, after quality expert Kaoru Ishikawa, and teams often pair it with the 5 Whys.
- Related:5 WhysRoot causePareto chart
- Gemba
- Japanese for “actual place,” used in lean to mean wherever value-creating work actually happens: a factory floor, an operating room, a kitchen, a job site. It is also spelled genba.
- Related:Genchi genbutsuGemba walkValue
- Gemba walk
- A management practice of going to where the work happens to grasp the current situation through direct observation and questions before taking action. A useful approach is to follow one product or customer-facing process from start to finish across departments.
- Related:GembaGenchi genbutsuValue stream
- Genchi genbutsu
- The Toyota practice of understanding a situation by observing it firsthand at its source instead of relying only on reports or data. The phrase translates directly as “actual place and actual thing” and is usually summarized as “go and see.”
- Related:GembaGemba walk5 Whys
- Hansei
- Japanese for “self-reflection”: looking back at a process, project, or personal shortcoming to see how it can be improved. Toyota holds hansei meetings at milestones and at project ends, and the practice works the same way for a person reviewing their own week.
- Related:PDCA (Plan-Do-Check-Act)YokotenCountermeasure
- Heijunka
- Leveling the type and quantity of work over a fixed period, instead of building in large, uneven batches. For example, a producer that receives 500 orders a week, unevenly by day, might hold a small buffer and make 100 a day.
- Related:MuraTakt timeKanban
- Hoshin kanri
- A strategy deployment method, also called policy deployment, that links an organization's main objectives to the work of every level and department using PDCA thinking. Goals and resources are negotiated back and forth between leaders and teams, a dialogue often called catchball.
- Related:A3 reportPDCA (Plan-Do-Check-Act)Yokoten
- Improvement kata
- A repeating four-step routine for practicing scientific improvement: define a challenge, grasp the current condition, set the next target condition, and run experiments toward it. Mike Rother introduced it to the lean community, with a companion coaching kata, in his 2010 book Toyota Kata.
- Related:Target conditionPDCA (Plan-Do-Check-Act)Hansei
- Jidoka
- One of the two pillars of the Toyota Production System: giving machines and people the ability to detect an abnormality and stop work immediately, so defects are not passed on and problems get fixed at their source. Toyota describes it as “automation with a human touch,” and it traces back to Sakichi Toyoda's looms, which stopped when a thread broke.
- Related:Toyota Production System (TPS)AndonPoka-yoke
- Just-in-time (JIT)
- The second pillar of the Toyota Production System: making only what is needed, when it is needed, and in the amount needed. The idea is credited to Kiichiro Toyoda in the 1930s, and it relies on pull, takt time, and continuous flow.
- Related:Toyota Production System (TPS)Pull productionTakt time
- Kaikaku
- Radical, fast improvement of a value stream, such as rearranging equipment over a weekend to create a new flow cell. It is sometimes called breakthrough kaizen, in contrast to gradual, step-by-step kaizen.
- Related:KaizenKaizen eventValue stream
- Kaizen
- A Japanese word meaning “continuous improvement”: making small, incremental improvements to processes and systems, with everyone involved. Masaaki Imai introduced the term to Western readers in his 1986 book Kaizen: The Key to Japan's Competitive Success.
- Related:Continuous improvementKaikakuPDCA (Plan-Do-Check-Act)
- Kaizen event
- A focused team improvement effort, commonly lasting about five days, in which a team studies a process at the gemba, implements a significant change, tests it, and standardizes it. It is also called a kaizen workshop or kaizen blitz; it works best alongside daily kaizen, not as a substitute for it.
- Related:KaizenKaikakuStandardized work
- Kanban
- Japanese for “sign” or “signboard”: a signal, often a card, that authorizes making or moving items in a pull system. Production kanban tell a process what to make, while withdrawal kanban authorize moving parts to the next process.
- Related:Pull productionJust-in-time (JIT)Visual management
- Lead time
- The time it takes a product or request to move through a whole process from start to finish (also called throughput time). From the customer's side, order lead time is how long they wait; typically, the time something is actually being worked on is only a small fraction of it.
- Related:Cycle timeValue stream mapping (VSM)Continuous flow
- Lean production
- A way of organizing development, operations, suppliers, and customer relations that uses less effort, space, capital, and time than mass production while making fewer defects. The term was coined by John Krafcik, a research assistant at MIT, in the late 1980s and spread through the 1990 book The Machine That Changed the World.
- Related:Toyota Production System (TPS)Lean thinkingMuda
- Lean thinking
- A five-step approach set out by James Womack and Daniel Jones in 1996: specify value from the customer's view, identify the value stream, make the work flow, let the customer pull, and pursue perfection by repeating the cycle.
- Related:ValueValue streamPull production
- Muda
- Japanese for waste: any activity that consumes resources without creating value for the customer. Lean practice distinguishes waste that can't be removed yet with current technology from waste that can be eliminated quickly through kaizen.
- Related:Seven wastesMuraMuri
- Mura
- Unevenness in an operation, such as a schedule that swings for reasons other than real customer demand, or a work pace that makes people hurry and then wait. Level scheduling is the usual remedy.
- Related:MudaMuriHeijunka
- Muri
- Overburden: pushing people or equipment harder, faster, or longer than they are designed or staffed to handle. Muda, mura, and muri are often discussed together because fixing one tends to reduce the others.
- Related:MudaMuraStandardized work
- Pareto chart
- A chart that combines bars showing how often each cause of a problem occurs with a line showing their cumulative percentage. Named for Vilfredo Pareto, it helps a team decide which few causes to tackle first.
- Related:Fishbone diagramRoot cause
- PDCA (Plan-Do-Check-Act)
- A four-step improvement cycle: plan a change, do it, check the results, and act by standardizing the change or starting the cycle again. Japanese executives recast the cycle W. Edwards Deming taught at a 1950 seminar sponsored by the Japanese Union of Scientists and Engineers (JUSE) into PDCA, and Ronald Moen's history dates the Japanese PDCA cycle to 1951; no single person claims authorship.
- Related:PDSA (Plan-Do-Study-Act)Standardized workKaizen
- PDSA (Plan-Do-Study-Act)
- W. Edwards Deming's version of the improvement cycle, which puts “Study” in place of “Check” to stress learning: predict what a change will do, test it, study the actual results against the prediction, then adjust. It builds on a cycle Walter Shewhart published in 1939; Deming refined his version from 1986 to 1993, and in a 1990 letter he wrote, “be sure to call it PDSA, not the corruption PDCA.”
- Related:PDCA (Plan-Do-Check-Act)System of Profound KnowledgeBaseline
- Point-of-use storage
- Keeping parts, tools, and materials as close as possible to where they are used. The same principle at home might mean keeping coffee filters beside the coffee maker rather than in a cupboard across the room.
- Related:5SSeven wastesVisual management
- Poka-yoke
- Japanese for mistake-proofing: simple, inexpensive devices or designs that make errors hard to commit or easy to spot, such as a part that only fits one way. Some stop the process when an error occurs; others warn with a light or buzzer.
- Related:JidokaRoot causeStandardized work
- Pull production
- A way of controlling work in which downstream steps signal what they need and upstream steps make nothing until that signal arrives. It aims to prevent overproduction, and it is the opposite of push production, which builds to forecasts regardless of what the next step needs.
- Related:KanbanJust-in-time (JIT)Seven wastes
- Quality control circle
- A small group of workers and their team leader who meet regularly to identify, analyze, and solve problems in their own work area. At Toyota, circles are built into the wider quality system rather than run as a stand-alone program.
- Related:KaizenPDCA (Plan-Do-Check-Act)Training Within Industry (TWI)
- Red tagging
- Labeling items that may not be needed during the sort step of 5S. Tagged items move to a holding area, where they are reassigned elsewhere or discarded if nobody needs them.
- Related:5SPoint-of-use storage
- Root cause
- The underlying reason a problem happens, as opposed to its visible symptoms. Fixing the root cause is meant to stop the problem from recurring, while fixing only a symptom (replacing a blown fuse, say) invites the same failure again.
- Related:5 WhysFishbone diagramCountermeasure
- Seven wastes
- Taiichi Ohno's seven categories of waste: overproduction, waiting, conveyance (unnecessary transport), overprocessing, excess inventory, unnecessary motion, and correction (inspection, rework, and scrap). Ohno considered overproduction the worst because it creates and hides the others.
- Related:MudaWork-in-process (WIP)Pull production
- SMED (single-minute exchange of die)
- A method for cutting changeover time, the time to switch a machine or process from one product to the next, ideally to under 10 minutes. Shigeo Shingo's key insight was to separate setup steps that require stopping from those that can be done while the process is still running, then convert as many as possible to the second kind.
- Related:Lead timeHeijunkaStandardized work
- Standardized work
- Precise, documented procedures for how each person's work is done, built in production settings on takt time, the work sequence, and the standard inventory needed. It provides the baseline for kaizen: when a team finds a better method, it updates the standard so the gain sticks.
- Related:Takt timeBaselineBasic stability
- System of Profound Knowledge
- W. Edwards Deming's theory of management, articulated in the late 1980s and early 1990s and explained in his book The New Economics. It ties together four areas: appreciation for a system, knowledge of variation, theory of knowledge, and psychology.
- Related:Deming's 14 PointsPDSA (Plan-Do-Study-Act)
- Takt time
- Available working time divided by customer demand. If a shop works 480 minutes a day and customers want 240 units, takt time is two minutes, which sets the pace production should match. Takt is German for a precise interval, as in a musical beat.
- Related:Cycle timeStandardized workJust-in-time (JIT)
- Target condition
- A specific description of how a process should work at a near-term point, set as a step toward a bigger challenge. In the improvement kata, learners typically set one about two weeks out and experiment their way toward it.
- Related:Improvement kataBaselineCountermeasure
- Toyota Production System (TPS)
- The production system Toyota developed to deliver high quality, low cost, and short lead times by thoroughly eliminating waste. It rests on two pillars, just-in-time and jidoka, and Toyota traces its roots to Sakichi Toyoda's automatic loom and Kiichiro Toyoda's just-in-time concept. Toyota credits Taiichi Ohno, backed by Eiji Toyoda, with helping establish the system; the Lean Enterprise Institute dates Ohno's development work to the 1950s and 1960s.
- Related:JidokaJust-in-time (JIT)Lean production
- Training Within Industry (TWI)
- A set of US training programs developed during World War II to help companies train large numbers of new workers quickly. Its three “J” programs (Job Instruction, Job Methods, and Job Relations) were later adopted by Japanese companies, including Toyota.
- Related:Standardized workQuality control circle
- Value
- The worth of a product or service as judged by the customer. A value-creating activity is one the customer would miss if it were left out; activities that add cost but no value in the customer's eyes are targets for elimination.
- Related:MudaValue streamLean thinking
- Value stream
- All the actions, both value-creating and not, needed to bring a product or service from order to delivery (or from concept to launch). It includes the information steps, such as processing orders, as well as the physical work.
- Related:Value stream mapping (VSM)ValueLead time
- Value stream mapping (VSM)
- Diagramming every step in the material and information flows that bring a product from order to delivery, to find and remove waste. Teams usually draw a current-state map of how work flows today, then a future-state map of how it should flow; Toyota calls its version a material and information flow diagram.
- Related:Value streamLead timeKaizen event
- Visual management
- Placing tools, parts, work activities, and performance indicators in plain view, so anyone can see the status of a process at a glance. At home, a wall calendar or a chore chart applies the same idea.
- Related:Andon5SKanban
- Work-in-process (WIP)
- Items of work sitting between processing steps. Lean practice keeps a defined minimum of WIP to keep work flowing smoothly; extra WIP is a form of inventory waste.
- Related:Continuous flowSeven wastesPull production
- Yokoten
- Spreading a lesson, fix, or good idea sideways across an organization. For example, if one machine has a defective valve, yokoten means checking every similar valve in the building and other sites too.
- Related:HanseiStandardized workHoshin kanri