Lean vocabulary: the dictionary for your organization's performance

A way of regulating the working relationship between two machines or operators that controls overproduction and ensures the balanced use of resources.

See : Inventory, Overproduction.

A visual management tool that shows the status of operations in an area at a single location and signals when something abnormal occurs.

See : Jidoka, Visual Management.

Ensures that a production process stops whenever a problem or defect occurs. On an automated line, this usually means installing sensors and buttons that automatically stop the line when an abnormality is detected.

See: Error-Proofing, Fixed-Position Stop System, Jidoka.

Production facilities usually managed according to the philosophy of mass production.

Compare with : Greenfield.

A location where the processing steps for a given item take place immediately one after another, so that parts, documents, etc. can move in a flow very close to continuous, whether one unit at a time or in small batches, maintained throughout the complete processing sequence.

See: Continuous Flow, Operator Balance Chart, Standardized Work.

A method of conducting one-piece flow in a cell in which the 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 it, thereby saving time and motion.

See : Cell, Continuous Flow.

Leader of a lean transformation with the authority and initiative to undertake the fundamental changes. The change agent, who often comes from outside the organization, does not need in-depth knowledge of lean philosophy at the start of the transformation.

Compare with: Sensei.

The process of switching production from one product to another on a machine (for example, a press or an injection molding machine) or on a series of linked machines (an assembly line or cell) by changing parts, dies, fixtures, molds, etc. (Also known as setup.) Changeover time is measured as the time elapsed between the last part of the run just completed and the first good part after the changeover.

See : Single-Minute Exchange of Die - SMED.

Term used at Toyota for the manager with full responsibility for the development and success of a product line; formerly known by the Japanese term shusa.

See : Value Stream Manager.

Producing and moving one item at a time (or a small batch of items) through a series of processing steps as continuously as possible, with each step making just what is requested by the next step.

See : One-Piece Flow, Batch and Queue, Flow Production.

A tendency observed in multi-step processes, in which the production orders received by each upstream process are more erratic than the actual production or sales of the downstream steps. Also known as the Forrester Effect (after Jay Forrester of MIT, who first characterized this phenomenon mathematically in the 1950s) and the Bullwhip Effect.

See: Build to Order, Heijunka, Level Selling.

Collaboration between customer and supplier to design a component and its production process.

See : Resident Engineer.

Production time lost due to stoppages, whether planned or unplanned. Planned downtime includes scheduled stoppages for activities such as start-of-shift production meetings, changeovers and maintenance. Unplanned downtime includes stoppages due to breakdowns, machine adjustments, material shortages and absenteeism.

See: Overall Equipment Effectiveness (OEE), Total Productive Maintenance (TPM).

Meeting customer requirements exactly with the minimum amount of resources.

See : Overproduction, Seven Wastes.

Methods that help operators avoid mistakes in their work, such as choosing the wrong part, assembling a part incorrectly, forgetting a component, etc. Also known as poka-yoke (defect-proofing) or baka-yoke (foolproofing).

See : Inspection, Jidoka.

The frequency with which each part is produced in a production process.

See: Heijunka.

The principle and practice of maintaining precision in the sequence of production and material movement, ensuring that the first part to enter a process or storage location is also the first part to exit. This ensures that stored parts do not become obsolete and that quality problems are not hidden in inventory. FIFO is a necessary condition for implementing a pull system.

See: Kanban, Pull Production

The practice of asking "why?" repeatedly whenever a problem is encountered, in order to go beyond the obvious symptoms and thereby discover the root cause.

See: Kaizen, PDCA.

A method of dealing with problems on production lines by stopping the line at the end of the work cycle, that is, at a set position, if a problem is detected and cannot be solved within the work cycle.

See: Andon, Automatic Line Stop, Jidoka.

Leveling the type and quantity of production over a fixed period of time. This enables production to efficiently meet customer demands while avoiding excess inventory and reducing costs, labor, and production lead time throughout the value stream.

See : Demand Amplification, Every Part Every Interval (EPEx), Just-in-Time (JIT), Muda, Mura, Muri, Single-Minute Exchange of Die - SMED.

A tool used to level the mix and volume of production by distributing kanban at fixed intervals. Also known as a leveling box.

See: Every Part Every Interval (EPEx), Heijunka, Kanban, Material Handling, Paced Withdrawal, Pitch.

Materials (and information) present along a value stream between processing steps.

Physical inventory is usually categorized by its position in the value stream and by its purpose. Raw materials, work-in-process and finished goods are terms used to describe the position of inventory in the production process. Buffer stock, safety stock and shipping stock are terms used to describe the purpose of inventory.

A measure of how quickly materials are moving through a plant or through an entire value stream, calculated by dividing a given cost measure by the amount of inventory on hand.

See : Inventory.

Providing machines and operators with the ability to detect when an abnormal condition has occurred and immediately stop work. This enables operations to build quality into the product at each step of the process and separates people from machines for more efficient work. Jidoka is one of the two pillars of the Toyota Production System, along with Just-in-Time.

See : Andon, Error-Proofing, Automatic Line Stop, Inspection, Just-in-Time (JIT), Multi-Process Handling, Toyota Production System, Visual Management.

A production system that makes and delivers only what is needed, when it is needed, and in the amount needed. JIT and Jidoka are the two pillars of the Toyota Production System. JIT relies on heijunka and is made up of three operating elements: the pull system, takt time, and continuous flow.

See : Continuous Flow, Heijunka, Jidoka, Pull Production, Takt Time, Toyota Production System.

A group kaizen activity, commonly lasting five days, in which a team identifies and implements significant improvements in a process.

See: Gemba, Jishuken, Kaizen, PDCA.

The basic learning cycle of lean product and process development, comprising five classes of development activity: look, ask, model, discuss, and act.

See : Lean Product and Process Development.

An attitude toward customers which assumes that demand for many products is relatively stable but is often disrupted by the production and sales systems themselves.

See : Demand Amplification, Heijunka, Make-to-Order.

A situation in which the production lead time and the order lead time are shorter than the time the customer is willing to wait for the product, so the manufacturer builds to confirmed orders rather than to a forecast.

See: Demand Amplification, Heijunka, Level Selling.

The movement of physical items along the value stream. In mass production, products travel to centralized processes in large batches, pushed by instructions from a master schedule. In lean production, the process steps for different product families are carried out, whenever possible, in a tightly defined sequence of processes, so that small quantities of product can flow directly from step to step, pulled by the next downstream process and by the end customer.

See : Information Flow, Just-in-Time (JIT), Lean Production, Mass Production.

Three terms often used together in the Toyota Production System (known as "the three Ms") that collectively describe wasteful practices to be eliminated.

See: Heijunka.

A work practice in which operators run more than one machine in a layout of process islands. It requires separating human work from machine work and is normally made easier by applying jidoka and auto-eject devices on the machines.

See: Jidoka, Multi-Process Handling.

A work practice in which operators work on more than one process in a layout oriented to the flow of products. It requires training operators to handle different types of machines (e.g., cutter, polisher, tester, etc.) so that they can move products through the cellularized operations.

See: Multi-Machine Handling.

Tasks in processes with many operators that require him or her to interrupt the work rhythm or leave the area.

See : Standardized Work.

Work performed on an item by a machine or a person.

See: Process.

Operational availability is the fraction of time a machine works properly when needed. Operating rate is the amount of time in a given period (shift, day, etc.) that a machine is used.

See : Overall Equipment Effectiveness (OEE).

A graphical tool that helps create continuous flow in a multi-step, multi-operator process by distributing the operator's work elements in relation to takt time. Also known as an operator loading diagram or yamazumi board.

See: Yamazumi Board.

A total productive maintenance (TPM) metric that measures how effectively a piece of equipment is used.

See : Total Productive Maintenance (TPM).

Producing more, sooner, or faster than is required by the next process. Ohno considered overproduction the most serious form of waste because it generates and hides other wastes, such as inventory, defects, and excess transportation.

See: Batch and Queue, Ohno, Seven Wastes.

The practice of releasing production orders to work areas and withdrawing finished goods from those areas at a fixed, frequent pace. This practice can be used as a way to link material flows to information flows.

See: Every Product Every Interval, Heijunka Box, Milk Run, Pull Production.

Any process in a value stream that sets the pace for the entire stream. (The pacemaker process should not be confused with a bottleneck process, which necessarily constrains downstream processes due to a lack of capacity.)

See: First In, First Out.

The number of items a customer (whether internal or external) wants packed and stored in a container for transport and shipping. Note that a pallet of a product may consist of numerous containers.

See : Pitch.

The amount of time needed in a production area to make one container of products. The formula for pitch is:

Takt time x pack-out quantity = pitch See : Heijunka Box, Paced Withdrawal, Pack-Out Quantity, Takt Time.

A detailed plan for each part used in a production process, showing every detail relevant to managing the process without errors or waste. It is a fundamental tool of the Toyota Production System.

See: Material Handling, Pack-Out Quantity.

A program for training and developing employees that shows the skills required and the skills already developed.

See: Multi-Process Handling.

Grouping of activities by type, rather than in the sequence needed to design or make a product.

See: Mass Production, Material Flow.

A product and its variants that pass through similar processing steps and common equipment just prior to shipment to the customer. The significance of product families for lean thinkers is that they are the unit of analysis for value stream maps, which are defined starting from the last step before the customer.

See: Product Family Matrix and Value Stream Mapping.

A board, usually a large whiteboard, placed next to a process to show actual performance compared with planned performance.

See: PDCA.

A disciplined method for designing a lean production process for a new product, or for fundamentally redesigning the production process for an existing product when the product or demand changes substantially. It may also be called Lean Process Development.

See: Kaizen, Kaizen Workshop.

Processing large batches of products at maximum speed, based on forecast demand, and moving them to the next downstream process or into storage, regardless of the actual pace of work in the next process. Batch and Queue, Production Control.

See : Batch and Queue, Production Control.
Compare with : Pull Production.

Tagging unnecessary items in order to remove them from a production area during a 5S exercise.

See : 5S.

A pull production system in which upstream (supplier) processes produce only enough to replace or replenish the product withdrawn by downstream (customer) processes.

See: Kanban, Pull Production, Supermarket.

Highly capable process equipment that is easy to maintain (and therefore available to produce whenever needed), allows quick changeovers, is easy to move and is designed to be installed in small increments of capacity, in order to facilitate labor and capital linearity.

See : Capital Linearity and Labor Linearity.
Compare with : Monuments.

An approach to designing products and services in which developers consider sets of ideas rather than a single idea.

See : Trade-off curves.

The process of reducing the time needed to change a process over from one model to another, from the last piece of the previous product to the first good piece of the next product.

See: Changeover, Single-Minute Exchange of Die (SMED).

Taiichi Ohno's categorization of the seven major wastes commonly found in mass production: overproduction, waiting, transportation, processing, inventory, motion and correction.

See: Changeover, Setup Reduction.

An engineer and consultant whose books and teachings were key contributions to the dissemination of the Toyota Production System.

See: Setup Reduction, Single-Minute Exchange of Die - SMED.

A project leader, like the chief engineer in Toyota's product development system.

See: Chief Engineer.

A process for changing production equipment over from one part to another in the shortest possible time. SMED refers to the goal of reducing changeover times to a single digit, or less than 10 minutes.

See : Changeovers, Setup Reduction, Shingo.

A diagram of the path a product takes as it moves along a value stream. It is so called because, in mass production, the route of products often looks like a plate of spaghetti.

See : Material Flow.

Available production time divided by customer demand. For example, if a factory operates 480 minutes per day and customer demand is 240 units 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 by providing a rhythm for the production system. It is the heartbeat of a lean system.

See: Cycle Time, Heijunka, Just-in-Time Production, Operator Balance Chart, Pacemaker Process, Pitch, Takt Image.

The son of Sakichi Toyoda, founder of the Toyota group, he led the company's effort to enter the automotive industry in the 1930s. Kiichiro believed it was possible to sustain the entire production process with just the needed stock of products if the preceding process simply responded to the exact needs of the next downstream process. He called this system Just-in-Time, which became one of the two pillars of the Toyota Production System.

See : Toyoda, Sakichi; Toyota Production System.

Founder of the Toyota group, he invented a self-monitoring device for the looms in his factory in the early 20th century that stopped the machines if a thread broke. This innovation allowed one operator to run several machines and led to the concept of Jidoka, which means "automation with human intelligence." It is one of the two pillars of the Toyota Production System.

See : Toyoda, Kiichiro; Toyota Production System.

A production system developed by Toyota Motor Corporation to provide the best quality, the lowest cost and the shortest lead time through the elimination of waste. TPS is built on two pillars, Just-in-Time and Jidoka, and is usually illustrated by the "house" shown below. TPS is maintained and improved through iterations of standardized work and kaizen, following PDCA, or the scientific method.

See : Jidoka; Just-in-Time Production; Lean Production; Ohno, Taiichi.

An organization’s strategic and philosophical vision or purpose.

It is a link that can include "hard" business objectives, such as revenue and profit, as well as visionary goals that appeal to the emotions. (Adapted from Dennis 2007).

An individual with clear responsibility for the success of a value stream. The value stream can be defined at the product or business level (including product development), or at the plant or operations level (from raw materials to delivery). The value stream manager is the architect of the value stream, identifying value as defined by the customer and leading the effort to achieve an ever leaner flow.

See : Chief Engineer.

Placement of all tools, parts, production activities and performance indicators of the production system in an easily visible location, so that the actual situation can be quickly understood by everyone involved.

See : Andon, Jidoka.

Any activity that consumes resources but creates no value for the customer. Most activities are waste (muda). There are two types of waste: type 1 and type 2. Type 1 muda creates no value but is unavoidable in a given situation. An example would be inspecting welds to ensure quality.

See : Muda, Seven Wastes.

Yamazumi is the Japanese term for "pile" or "heap".

See : Operator Balance Chart.