Lean production constitutes a language, much of which is Japanese. Words in the Japanese language tend to be visual and symbolic, and often, there are no English equivalents. The definitions featured in this glossary are intended to provide the nearest English equivalent as well as the most vivid metaphor to convey the meaning as closely as possible.
Affinity diagram: A tool for collecting and combining ideas; one of the seven quality tools used in Hoshin planning (see Hoshin kanri).
A3 thinking: This type of thinking is typically a problem-solving, decision-making, and collaborative management tool. “A3” refers to the A3-sized paper that outlines goals, ideas, problems, and solutions employed in this process.
Andon: Workers can use this mechanism to immediately stop the production line or process once a defect is detected. This is an excellent example of jidoka, which elevates the importance of immediate action to prevent defects from escalating.
Check gambutsu: Examining physical objects in the Gemba during the fact-finding process to determine the root cause of problems.
Continuous flow: In the purist, materials are processed and moved directly to succeeding processes one unit at a time; each step completes its work just before the next step needs the unit. The transfer batch size is one (1), also known as one-piece flow (make one, move one).
Conformance: A positive indicator that a product or service quality meets the requirements of a specification, contract, or regulation.
Control chart: A chart with top and bottom limits on which values of some statistical measures for a series of data are plotted. The control chart shows a central line to help identify a trend of values towards either control boundaries.
Cost: When used in the context of quality, cost, and delivery (QCD), the word “cost” usually refers to cost management and not cost-cutting. Cost management involves managing various resources properly and eliminating all sorts of muda so that the overall cost decreases.
Cross-functional management: A leadership approach that unites team members from different functional areas to achieve a common goal. This collaboration breaks down departmental silos, enhances communication, and leverages diverse expertise for better outcomes.
Cycle time: The actual time an operator takes to process a piece of product.
Delivery: When used in the context of QCD, the word “delivery” refers to meeting a customer’s delivery and volume requirements.
Don’t accept it, don’t make it, don’t send it. A common-sense slogan to be implemented in the Gemba that puts into practice the belief that quality is the priority in any program of QCD. For example, don’t accept inferior quality from the previous process, don’t make rejects in one’s product, and if a reject has been produced, don’t knowingly send it to the following procedure.
Failure tree analysis: Failure tree analysis is used to analyze and avoid safety and reliability problems in advance by identifying cause and effect relationships and the probability of the issues using the tree diagram.
4 M’s: Man/woman, machine, material, and method.
5 golden rules of Gemba management: Also known as “Gemba Kaizen,” this is a set of the most practical reminders by implementing Kaizen in the Gemba: (1.) Go to the Gemba when problems arise, (2.) check gambutsu, (3.) take temporary countermeasures on the spot, (4.) find and eliminate the root cause, and (5.) standardize to prevent reoccurrence.
5 Why’s: A method of root cause analysis used in problem-solving in which the question “why” is asked five times repeatedly until the underlying cause is determined.
5M’s: A method for managing resources in the Gemba. It stands for manpower, machine, material, method, and measurements.
5S’s: A checklist for Good Housekeeping to achieve greater order, efficiency, and discipline in the workplace. It is derived from Japanese words and adapted to English equivalents of sort, set in order, shine, standardize, and sustain.
Flow production: One of the fundamental pillars of the JIT production system. Machines are arranged in the order of processing so that the workflow of the workpiece flows between processes without interruption or stagnation.
Gemba: A Japanese word meaning “real place” and now adapted to convey “workplace” where value is added. In production, it usually refers to the plant floor.
Gembutsu: The tangible objects in the Gemba are workpieces, rejects, jigs, tools, and machines. It is also sometimes written as “Genbutsu.”
Go to the Gemba: The first principle in the Gemba Kaizen continuous improvement philosophy. This is a reminder that whenever an abnormality occurs or a manager wishes to know the current state of operations, they go to the Gemba immediately because Gemba is the source of all information.
Heinrich’s law: A principle related to the occurrence ratio of accidents. With injuries, Heinrich explains the ratio as follows:
Serious injury: minor injury: no injury = 1: 29: 300
This equation expresses that when you see one person seriously injured by an accident, the same accident might have hurt 29 people slightly. At the same time, there might have been 300 people who, luckily, were not injured but experienced the same accident.
Hoshin kanri: A management system that helps an organization remain competitive year after year by keeping the entire organization aligned and focused on achieving well-defined and shared goals. It starts with the firm strategy, then several-year goals, and then cascades vertically and horizontally so everyone has aligned objectives for each year. Individual improvement efforts should be aimed not only at making the person more productive and effective but also at achieving the organization’s overall goals. The planning process and execution provide leaders opportunities to coach at each level and develop people.
Industry 4.0: This refers to connecting intuitive “Smart” production systems designed to sense, predict, and interact with the physical environment to make decisions that support production in real-time. In manufacturing, it can increase productivity, energy efficiency, and sustainability.
IoT (Internet of Things): The concept of connecting any device to the Internet and other connected devices. This includes everything from cell phones to manufacturing equipment and vehicles. Advanced systems use cameras and sensors to collect data and artificial intelligence to analyze the data and provide direction (for example, equipment maintenance).
Ishikawa (fishbone) diagram: Initially developed by Professor Kaora Ishikawa to show causes (process) and effects (result), this chart determines the natural causes. It is one of the seven essential problem-solving tools.
Jidoka (automation): A device that stops a machine whenever a defective product is produced. This device is essential in introducing just-in-time (JIT).
Jishu kanri: Means “autonomous management” in Japanese and refers to workers’ participation in Kaizen activities as a part of their daily activities under the guidance of a line manager; it is different from quality circle activities, which are voluntary and are carried out by the worker’s own accord.
JIT: Just-in-time (JIT) is a system designed to achieve the best possible quality, cost, and delivery of products and services. It eliminates all kinds of muda in a company’s internal processes and delivers products just-in-time to meet customers’ requirements. Initially developed by Toyota Motor Company, it is also called the Toyota Production System, the Lean Production System, and the Kanban system.
Juno: The Japanese word for “sequence.” This logistics system prepares and delivers materials to the line or point-of-use in the use sequence.
Kaizen concepts: Major concepts that must be understood and practiced by implementing Kaizen:
Kaizen story: A standardized problem-solving procedure to be used at each level of an organization. A Kaizen story has eight steps: (1.) Select a project, (2.) understand current situations and set objectives, (3.) analyze data to identify root causes, (4.) establish countermeasures, (5.) implement countermeasures, (6.) confirm the effect, (7.) standardize, and (8.) review the preceding process and work on the next steps.
Kaizen systems: Major systems must be established to attain a world-class status:
Kata: This word has two meanings. One is in the form or way of doing things, and the second is the pattern of movements to be practiced in developing a fundamental skill. The improvement kata (IK) model consists of four steps that reflect thinking scientifically about the direction of the current situation. Short-term targets and experimental practice routines have been designed for the coaching kata (CK) centered on questions that help the coach keep the learner on track, following the kata until thinking scientifically comes naturally.
Kanban: A communication tool in the JIT system whenever batch production is involved. The word means “signboard” in Japanese and is attached to a given process in the production line, instructing the delivery of a given quantity. When the parts have been consumed, the Kanban is restored to its standard, where it becomes an order to produce more.
Kosu: Manufacturing operations can be divided between machine hours and personal hours. Kosu refers to the specific personal hours to produce one product unit in a given process. It is calculated by multiplying the number of workers involved in an operation by the actual time it takes to complete the process and dividing that number by the units produced. It is used as a measure of operators’ productivity. Kosu reduction is one of the critical measures of productivity improvement in the Gemba.
KPIs: Key performance indicators (KPIs) is a common term in business that refers to a standard set of metrics and measurements used to support and facilitate an organization’s critical goals elevate performance. Toyota visually displays KPIs on graphs and charts and sets targets (for example, through Hoshin kanri) to motivate improvement activities.
Lean: The philosophy, tools, and techniques for thinking, organizing, and performing work that causes hidden waste to be illuminated. With the waste uncovered, a company can devise and implement strategies and practices to reduce or eliminate it. It is also called the Toyota Production System (TPS).
Morning market: A daily routine at the Gemba that involves examining rejects (Gembutsu) made the previous day before work begins so the countermeasures can be adopted as soon as possible based on Gemba Gembutsu principles. This meeting. involving the Gemba people and not staff, is held first thing in the morning.
Muda: The Japanese word meaning “waste,” which, when applied to workplace management, refers to a wide range of non-value-added activities. In the Gemba, there are only two activities: value-adding and non-value-adding. In Gemba Kaizen, efforts are directed first to eliminate all non-value-adding activities. Eliminating muda in the following areas can significantly improve QCD: overproduction, inventory, rejects, motion, processing, waiting, transport, and time. Muda elimination optimizes the low-cost, common-sense approach to improvement.
Mura: The Japanese term for “unevenness.” There are various types of unevenness it addresses, for example, unevenness that results from an off-beat production schedule or fluctuating production volumes due to internal problems like downtime, missing parts or defects. It also relates to unevenness in production levels that makes it necessary to have on hand the equipment, materials, and people of the highest level of production—even if the average requirements are far less and the irregularity leads to too little work sometimes and overburden at other times.
Muri: Japanese for “overburdening” people or equipment. Muri is pushing machines or people beyond their natural limits. Overburdening people results in safety and quality problems, and overburdening equipment causes breakdowns and defects. In other words, Muri can cause muda (unevenness); even worse, overburdening people can cause health problems.
OEE: Overall Equipment Effectiveness (OEE) is a metric used to measure the effectiveness and performance of manufacturing processes or any individual piece of equipment. It supplies insights into how healthy equipment is used and how efficiently it runs in producing products or delivering services.
One-piece flow: Only one workpiece is allowed to flow from process to process to minimize muda in a JIT production system.
Pareto chart: A graphic tool for ranking causes from most to least significant. It is based on the Pareto rule that states 80% of effects come from 20% of the causes. The Perato chart is one of the seven essential tools of problem-solving.
PDCA: Plan-do-check-act (PDCA) are the basic steps to be followed in making continual improvement Kaizen.
Pull production: One of the basic requirements of the JIT production system. Here, the previous process produces only as many products as the following procedure consumes.
Push production: The opposite of pull production. This process produces as much as it can without regard to the requirements of the following procedure and sends them to the following method, whether there is a need or not.
QA Best-Line certification: An in-house certification system to certify a world-class quality assurance performance of a particular process.
QCD: Quality, cost, and delivery (QCD) are regarded as the ultimate goals of management. When management successfully achieves QCD, customer satisfaction and corporate success follow.
QCDMS: In the Gemba, M (morale) and S (safety) are often added to QCD as targets to be achieved.
QFD: Quality function deployment (QFD) is a management approach to identify customer requirements first and then work back through the stages of design, engineering, production, sales, and after-service of products.
Quality: In the context of QCD, “quality” refers to the quality of the products or services delivered to the customer. It touches on conformance to specifications and customer requirements. In a broader sense, “quality” refers to the quality of work in designing, producing, delivering, and servicing the products and services.
Quality circles: Quality improvement or self-improvement study groups composed of 10 or fewer employees. Quality circles originated in Japan and are called quality control (QC) circles. The QC circle voluntarily performs improvement activities within the workplace, carrying out its work continuously as part of a company-wide program of education, quality control, employee development, and productivity improvement.
Scientific thinking: Acknowledges that our comprehension is incomplete and the future is uncertain, so it works to test ideas and learn from the tests. Toyota takes a fact-based iterative learning approach to overcome complex challenges. Scientific thinking is at the center of Toyota’s 4P’s (philosophy, processes, people, and problem-solving).
SDCA: Standardize-do-check-act (SDCA) are the basic steps to be followed to maintain the current status.
Sensei: Honored teachers who have achieved mastery in a particular area. A Lean sensei has repeatedly demonstrated proficiency at the Gemba, whether they’re called a coach, a teacher, or a mentor. Lean sensei experts have been instrumental in teaching the Toyota Production System (TPS) within Toyota, particularly as it expanded among its suppliers into other countries.
Standardization: Documentation of the best ways to do a job. Standardization is one of the three fundamentals of Gemba Kaizen activities.
Standardized work: An optimal combination of worker, machine, and material. The three elements of standardized work are takt time, work sequence, and standard work in process.
Standards: The best way to do a job, namely, a set of policies, rules, directives, and procedures established by management for all primary operations that serve as guidelines enabling all employees to perform their jobs and ensure good results.
Storeroom: A place where work-in-process (WIP) and supplies are stored in the Gemba. A storeroom differs from an ordinary warehouse because only standardized inventory is kept there.
Suggestion system: Emphasizes morale-boosting benefits and positive employee participation over stressed economic and financial incentives. The suggestion system is a highly integrated part of individual-oriented Kaizen.
Takt time: The theoretical time in which a producer must produce a product ordered by a customer. Takt time is calculated by dividing the net available production time by the units required.
3M’s: Muda (“waste”), Mura (“unevenness” or “variation”), and Muri (“overburden”). These three words are used as Kaizen checkpoints to help workers and management identify the areas for improvement.
TPM: Total productive maintenance (TPM) strives to maximize equipment effectiveness throughout equipment life. It involves all departments at all levels and motivates people from plant maintenance through small-group and autonomous activities. Essential elements include developing a maintenance system, education, basic housekeeping, problem solving skills, and activities to achieve zero breakdowns and an accident-free environment. Autonomous maintenance by workers is one of the essential elements of TPM 5S and is an entry step of TPM.
TQC: Total quality control (TQC) organizes Kaizen activities on quality involving everyone in the company—managers and workers—in an integrated effort toward Kaizen at every level. These activities are assumed to ultimately lead to increased customer satisfaction and the business’s success.
TQM: For more information on total quality management (TQM), please see “TQC.”
Toyota Production System: Toyota’s unique approach to manufacturing and the basis for much of the Lean production movement that has dominated manufacturing and service trends for over 30 years. Led by Taiichi Ono, the Toyota Production System (TPS) was constructed in a time of low demand and a high need for variety in Japan, which necessitated a manufacturing approach that allowed for quick changeovers, low inventories, and flexibility based on the philosophies of jidoka and just-in-time. The Toyota Production System can efficiently produce products of good quality one at a time that fully satisfy customer requirements
Value analysis (VA): A method for cost reduction introduced by L.D. Miles at General Electric in 1947. It aims to reduce material and component costs at the upstream stages of designing and design reviews. Value Analysis involves cross-functional collaborations of product design, production, engineering, quality assurance, and manufacturing and is also employed for competitive benchmarking.
Value engineering (VE): A method and practice for cost reduction to achieve the original specification through alternative designs, strategies, and materials.
Visual management: An effective management method to provide information and gembutsu (“actual object”) visibly to workers and managers so that everybody understands the current state of operations and the target for Kaizen. It also helps people to identify abnormalities promptly.
Value stream mapping: A method to understand the material and information flow in a sequence of work processes. The current state map depicts how value flows to the customers and the various ways that are obstacles to this flow. The future state map is an aspirational vision of how material and information need to flow to achieve business objectives.
Zero loss thinking: A performance management mindset in which there is no acceptable level of failure: No poor quality. No breakdowns. No delays. No customer complaint processes. It is also known as “zero-based thinking.”
