Lean Glossary


3M (Muda, Muri, Mura)

MUDA means any form of waste (8 types : TIMWOOD U) : actions, activities that are not added value.
MURI means unreasonable / illogical burden of people or machines.
MURA means unlevelled workloads of people or machines, also known as variability or irregularity.

Mura and Muri lead to Muda. The purpose of Lean is to take out of the process those three ennemies.

5 Why?

It's a classic problem solving tool. It's useful, to deal with an issue, to ask "why" five times in order to reach root causes. For each "why", it is required to be on the "gemba" and to look at concrete data and things instead of guessing.


Five terms utilized to create a workplace suited for visual control and lean production.

1. Sort means to separate needed tools, parts, and instruction from unneeded materials and to remove the latter.
2. Simplify means to neatly arrange and identify parts and tools for ease of use.
3. Scrub means to conduct a cleanup campaign.
4. Standardize means to conduct Sort, Simplify, and Scrub at frequent intervals to maintain a workplace in perfect condition.
5. Sustain means to form the habit of always following the first Ss.The 5S philosophy focuses on effective work place organisation, simplifies work environment, reduces waste, while improving quality and safety.


8 types of waste

Transportation : unnecessary part movements between process steps, multiple handling.
Inventory : any raw material, work in progress (WIP) or finished goods which are waiting to be processed or shipped.
Motion : unnecessary movement of people within a process.
Waiting : people or parts waiting for a cycle to be completed, idle time.
Overproduction : producing sooner, faster or in greater quantities than the customer demand.
Overprocessing : processing beyond the standard required by the customer or with an inapropriate process, unnecessary process steps.
Defects : producing parts that require rework or that is scrapped.
Under-utilizing people : not following up or implementing employee ideas or suggestions.


A visual management tool that highlights the status of operations in an area at a single glance and that signals whenever an abnormality occurs. An andon can indicate production status (for example, which machines are operating), an abnormality (for example, machine downtime, a quality problem, tooling faults, operator delays, and materials shortages), and needed actions, such as changeovers. A typical andon, which is the Japanese term for “lamp,” is an overhead signboard with rows of numbers corresponding to work- stations or machines. A number lights when a problem is detected by a machine sensor, which automatically trips the appropriate light, or by an operator who pulls a cord or pushes a button. The illuminated number summons a quick response from the team leader. Colored lighting on top of machines to signal problems (red) or normal operations (green) is another type of andon.

Chaku - Chaku

The term literally means "load-load" in Japanese. It’s a method of conducting one-piece flow in a cell where machines unload parts automatically so that the operator (or operators) can carry a part directly from one machine to the next without stopping to unload the part, thus saving time and motion.


For instance, the first machine in a processing sequence automatically ejects a part as soon as its cycle is completed. The operator takes the part to the next machine in the sequence, which has just finished cycling and ejected its part. The operator loads the new part, starts the machine, and takes the ejected part to the next machine, which has just finished cycling and ejected its part and so on around the cell. 

Chaku - Datsu

The term literally means "load-load" in Japanese. It’s a method of conducting one-piece flow in a cell where machines unload parts automatically so that the operator (or operators) can carry a part directly from one machine to the next without stopping to unload the part, thus saving time and motion. For instance, the first machine in a processing sequence automatically ejects a part as soon as its cycle is completed. The operator takes the part to the next machine in the sequence, which has just finished cycling and ejected its part. The operator loads the new part, starts the machine, and takes the ejected part to the next machine, which has just finished cycling and ejected its part and so on around the cell. 



The Japanese term for “actual place,” where value-creating work actually occurs; also spelled genba.The term often is used to stress that real improvement requires a shop-floor focus based on direct observation of current conditions where work is done. For example, standardized work for a call center operator cannot be written at a desk in the HR office, but must be defined and revised on the gemba.

Gemba Kanri

The management of all Gemba elements at all levels according to Kaizen. It signifies what is involved, how we manage, who is concerned by short, mid and long term shopfloor management.


Japanese for 'actual thing' or 'actual product'. The tools, materials, machines, parts, and fixtures that are the focus of kaizen activity.



Japanese for 'the facts' or 'the reality'. The actual facts or the reality of what is happening on the shop floor and in the business.


Genchi Genbutsu

In Japanese, genchi genbutsu essentially means “go and see” but translates directly as “actual place and actual thing.”

This  practice of thoroughly understanding a condition by confirming information or data through personal observation at the source of the condition. For example, a decision maker investigating a problem will go to the shop floor to observe the process being concerned and interact with workers to confirm data and understand the situation, rather than relying solely on computer data or information from others. The practice applies to executives as well as managers. 


Hanedashi - (or Auto-Eject)

Device or means of automatic unload of the work piece from one operation or process, providing the proper state for the next work piece to be loaded. Automatic unloading and orientation for the next process is essential for a "Chaku-Chaku" line.


The continuous improvement practice of looking back and thinking about how a process or personal shortcoming can be improved; the Japanese term for “self-reflection.” In the Toyota Production System, hansei or reflection meetings typically are held at key milestones and at the end of a project to identify problems, develop countermeasures, and communicate the improvements to the rest of the organization so mistakes aren’t repeated. Thus, hansei is a critical part of organizational learning along with kaizen and standardized work. It sometimes is compared to “check” in the plan-do-check-act improvement cycle.


In Japanese, the word heijunka means, roughly, “levelization.”


Leveling the type and quantity of production over a fixed period of time. This enables production to efficiently meet customer demands while avoiding batching and results in minimum inventories, capital costs, manpower, and production lead time through the whole value stream.


"Compass" or "direction".


Providing machines and operators the ability to detect when an abnormal condition has occurred and immediately stop work. This enables operations to build in quality at each process and to separate men and machines for more efficient work. Jidoka is one of the two pillars of the Toyota Production System along with just-in-time.


Jidoka highlights the causes of problems because work stops immediately when a problem first occurs. This leads to improvements in the processes that build in quality by eliminating the root causes of defects.



Radical, revolutionary improvement of a value stream to quickly create more value with less waste; sometimes called kakushin. One example would be moving equipment over a weekend so that products formerly fabricated and assembled in batches in isolated process villages are made in single-piece flow in a compact cell.



Kaizen means Kai « take apart » and zen means « make good ».Continuous incremental improvement of an activity to create more value with less waste There are two levels of kaizen

System or flow kaizen focusing on the overall value stream. This is kaizen for management. Process kaizen focusing on individual processes. This is kaizen for work teams and team leaders.


Value-stream mapping is an excellent tool for identifying an entire value stream and determining where flow and process kaizen are appropriate.


A kanban is a signaling device that gives authorization and instructions for the production or withdrawal (conveyance) of items in a pull system. The term is Japanese for “sign” or “signboard.”Kanban cards are the best-known and most common example of these signals. They often are slips of card stock, sometimes protected in clear vinyl envelopes, stating information such as part name, part number, external supplier or internal supplying process, pack-out quantity, storage address, and consuming process address. A bar code may be printed on the card for tracking or automatic invoicing. Besides cards, kanban can be triangular metal plates, colored balls, electronic signals, or any other device that can convey the needed information while preventing the introduction of erroneous instructions.


Whatever the form, kanban have two functions in a production operation: They instruct processes to make products and they instruct material handlers to move products. The former use is called production kanban (or make kanban); the latter use is termed withdrawal kanban (or move kanban).



Continuity in Japanese.


The total time a customer must wait to receive a product after placing an order. When a scheduling and production system is running at or below capacity, lead time and throughput time are the same. When demand exceeds the capacity of a system, there is additional waiting time before the start of scheduling and production, and lead time exceeds throughput time.

Lean 6 Sigma

Two separate improvement initiatives that are very strong together


  • Lean - focus on improving the flow of value.

Principle-based methodology to eliminate waste in the flow.


  • 6 Sigma - Advanced tools & focused approach ;  Depth (understanding the details) ; focus on improving capability.

Rigor methodology and tools to solve problems in the flow


"U"-shape lines

Setting up machines to form a "U". This set-up offers a number of advantages (reduced surface, operator productivity, greater flexibility to volume, ...).

Model line or model zone

Line or zone where Lean is deployed:
organisation, principles, culture, management style, tools, physical modifications, information flow modifications. The interest of a model line is to be in a position to show, for a specific zone, the benefits of Lean, to convince and train the operators and promote its deployment. 

Autonomous Maintenance 

Maintenance operations performed by production operators, starting with basic operations (controls, fluid levels, cleaning, greasing). Maintenance operators should previously train the production counterparts. 

Visual Management 

The placement in plain view of all tools, parts, production activities,and indicators of production system performance, so the status of the system can be understood at a glance by everyone involved.

Mizuzumashi or waterspider or milkrun

A regular and cyclical production line supply system that allows to optimise indirect labour, stock as little as possible at the line edge to gain sapce and clear areas.


Manufacturing Quality Chart with all quality control data.


Obeya in Japanese means simply “big room.” At Toyota it has become a major project-management tool, used especially in product development, to enhance effective and timely communication. Similar in concept to traditional “war rooms,” an obeya will contain highly visual charts and graphs depicting program timing, milestones and progress to date, and countermeasures to existing timing or technical problems.


Project leaders will have desks in the obeya as will others at appropriate points in the program timing. The purpose is to ensure project success and shorten the PDCA cycle.



Making and moving one piece at a time. It enables quick detection of defects, short lead times of production, small material and inventory costs



Methods that help operators avoid mistakes in their work caused by choosing the wrong part, leaving out a part, installing a part backwards, etc. Also called mistake-proofing, poka-yoke (errorproofing) and baka-yoke (fool-proofing).Common examples of error-proofing include:
Product designs with physical shapes that make it impossible to install parts in any but the correct orientation.
Photocells above parts containers to prevent a product from moving to the next stage if the operator’s hands have not broken the light to obtain necessary parts.

Replenishment pull

In a replenishment pull system with kanban each process has a store - or supermarket - that holds an amount of each product it produces. Each process simply produces to replenish what is withdrawn from its supermarket.


The Japanese term for “teacher.” Used by Lean Thinkers to denote a master of lean knowledge as a result of years of experience in transforming the gemba (the place where work actually is done). The sensei also must be an easily understood and inspiring teacher.

Sequential Pull System

A sequential pull system—also known as a b-type pull system—may be used when there are too many part numbers to hold inventory of each in a supermarket. Products are essentially “made-to-order” while overall system inventory is minimized.In a sequential system, the scheduling department must set the right mix and quantity of products to be produced. This can be done by placing production kanban cards in a heijunka box, often at the beginning of each shift. These production instructions then are sent to the process at the upstream end of the value stream. Often this is done in the form of a “sequence list,” sometimes called a “sequential tablet.” Each following process simply produces in sequence the items delivered to it by the preceding upstream process. FIFO of individual products must be maintained throughout

Setup Reduction (SMED : Single Minute Exchange of Die)

The process of reducing the amount of time needed to changeover a process from the last part for the previous product to the first good part for the next product.

The six basic steps in setup reduction are:


1. Measure the total setup time in the current state.
2. Identify the internal and external elements, calculating the individual times.
3. Convert as many of the internal elements to external as possible.
4. Reduce the time for the remaining internal elements.
5. Reduce the time for the external elements.
6. Standardize the new procedure.

Standardised work

An agreed-upon set of work procedures that establishes the best method and sequence for each process.  Standardized work is implemented to maximize efficiency while simultaneously ensuring safe conditions.The available production time divided by customer demand. For example, if a widget factory operates 240 minutes per day and customers demand 120 widgets per day, takt time is two minutes.


Similarly, if customers want two new products per month, takt time is two weeks. The purpose of takt time is to precisely match production with demand. It provides the heartbeat of a lean production system.


Takt time first was used as a production management tool in the German aircraft industry in the 1930s. (Takt is German for a precise interval of time such as a musical meter.) It was the interval at which aircraft were moved ahead to the next production station.


The concept was widely utilized within Toyota in the 1950s and was in widespread use throughout the Toyota supply base by the late 1960s.


Tactical Implementation Plan (TIP) see above.

TPM (Total Productive Maintenance) 

A set of techniques, originally pioneered by Denso in the Toyota Group in Japan, to ensure that every machine in a production process always is able to perform its required tasks.The approach is termed total in three senses. First, it requires the total participation of all employees, not only maintenance personnel but line managers, manufacturing engineers, quality experts, and operators. Second, it seeks total productivity of equipment by focusing on all of the six major losses that plague equipment: downtime, changeover time, minor stops, speed losses, scrap, and rework. Third, it addresses the total life cycle of equipment to revise maintenance practices, activities, and improvements in relation to where equipment is in its life cycle. Unlike traditional preventive maintenance, which relies on maintenance personnel, TPM involves operators in routine maintenance, improvement projects, and simple repairs. For example, operators perform daily activities such as lubricating, cleaning, tightening, and inspecting equipment.

TPS (Toyota Production System)

The production system developed by Toyota Motor Corporation to provide best quality, lowest cost, and shortest lead time through the elimination of waste. TPS is comprised of two pillars, just-in-time and jidoka, and often is illustrated with the “house".TPS is maintained and improved through iterations of standardized work and kaizen, following PDCA, or the scientific method.

Development of TPS is credited to Taiichi Ohno, Toyota’s chief of production in the post-WW II period. Beginning in machining operations and spreading from there, Ohno led the development of TPS at Toyota throughout the 1950s and 1960s, and the dissemination to the supply base through the 1960s and 1970s. Outside Japan, dissemination began in earnest with the creation of the Toyota- General Motors joint venture—NUMMI—in California in 1984.

Lean transformation 

A change or mutation in management methods, the organisation, culture, physical flows, information flows, quality operations, towards the Lean principles for greater SQCDP operational efficiency.

Standardized work or standard work

Establishing precise procedures for each operator’s work in a production process, based on three elements : Takt time, which is the rate at which products must be made in a process to meet customer demand. The precise work sequence in which an operator performs tasks within takt time. The standard inventory, including units in machines, required to keep the process operating smoothly.


Overall Equipment Effectiveness (OEE)


A total productive maintenance (TPM) measure of how effectively equipment is being used.OEE is calculated from three elements: The availability rate measures downtime losses from equipment failures and adjustments as a percentage of scheduled time. The performance rate measures operating speed losses—running at speeds lower than design speed and stoppages lasting a few seconds. The quality rate expresses losses due to scrap and rework as a percentage of total parts run. These elements are multiplied to obtain OEE:


Availability Rate x Performance Rate x Quality Rate = OEE


OEE typically focuses on what are termed the six major losses—failures, adjustments, minor stoppages, reduced operating speeds,scrap, and rework—but some companies add other measures judged important to their business.


A simple diagram of every step involved in the material and information flows needed to bring a product from order to delivery.Value-stream maps can be drawn for different points in time as a way to raise consciousness of opportunities for improvement . A current-state map follows a product’s path from order to delivery to determine the current conditions. A futurestate map deploys the opportunities for improvement identified in the current-state map to achieve a higher level of performance at some future point.


In some cases, it may be appropriate to draw an ideal-state map showing the opportunities for improvement by employing all known lean methods including right-sized tools and value-stream compression.


A Japanese term for deploying concepts, ideas, or policies horizontally across the company. For example, imagine a defective valve is found on one machine in the plant. Yokoten would be the process to ensure that all similar valves in the facility and other relevant facilities are examined for the same defect as well.


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