Art of Lean
Art Smalley presenting A Kaizen Mind Must Be Developed
C

Catchball

キャッチボール method

The back-and-forth dialogue between management levels used to align goals, plans, and targets — ensuring that objectives set at one level are understood, challenged, and committed to at the next level before being finalized.

Challenge

チャレンジ concept

One of the five core values of the Toyota Way — forming a long-term vision, meeting challenges with courage and creativity, and maintaining the spirit to realize dreams through sustained effort rather than settling for the status quo.

Check Sheet

チェックシート tool

One of the 7 QC Tools — a structured form designed for systematic data collection at the source. The simplest of the quality tools but arguably the most important: it forces disciplined, organized data collection before analysis begins, ensuring that subsequent tools like Pareto charts and histograms are built on facts, not impressions.

Control Chart

管理図 tool

One of the 7 QC Tools — a time-series plot with statistically calculated upper and lower control limits that distinguishes between normal process variation (common cause) and abnormal variation (special cause). Invented by Walter Shewhart at Bell Labs in 1924 and brought to Japan by W. Edwards Deming.

Cutting Point Management

加工点マネジメント tool

The third pillar of Toyota's 3 Pillar Activity — management of cutting tools, jigs, fixtures, and the tool-to-product interface at the point where quality is physically created, targeting first-shot accuracy and prevention of defects at their source.

Cycle Time

サイクルタイム concept

The actual measured time required to complete one cycle of an operation — either the operator's complete work sequence or the machine's automatic processing time. Cycle time is observed and measured, not calculated from demand.

J

Jidoka

自働化 concept

One of the two pillars of the Toyota Production System — the principle of building quality into the process by enabling machines and people to detect abnormalities and stop immediately, preventing defects from flowing downstream.

Jishuken

自主研 method

A hands-on group study activity where managers and engineers go to the shop floor to study and improve actual processes — learning TPS by doing, not by classroom instruction. Jishuken was a primary method Toyota used to develop TPS capability in its suppliers.

Job Instruction (TWI-JI)

仕事の教え方 method

A four-step method for teaching a person to do a job correctly, safely, and conscientiously — developed in the U.S. during World War II, transferred to Japan during the occupation, and deeply embedded in Toyota's approach to operator training.

Job Methods (TWI-JM)

改善の仕方 method

A structured four-step method for improving how a job is done — by breaking the job into details, questioning every detail, developing a new method, and applying it — developed as part of the TWI program and adopted at Toyota as a foundation for systematic improvement.

Job Relations (TWI-JR)

人の扱い方 method

A four-step method for handling people problems in the workplace — based on the principle that a supervisor's results depend on the people they work with, and that good relations are built by treating people as individuals and handling problems early with facts.

Just-in-Time

ジャストインタイム concept

One of the two pillars of the Toyota Production System — the principle of making only what is needed, when it is needed, in the amount needed, by synchronizing every process to the rate of customer demand.

K

Kaizen

改善 method

The practice of continuous, incremental improvement by every person, every day — not a special event but the daily discipline of working from a standard, finding problems, and establishing a better standard.

Kamishibai

紙芝居 method

A card-based audit system where managers draw cards representing specific standards, processes, or areas to check — ensuring that audits cover all critical items over time through randomized or scheduled rotation rather than relying on memory or personal preference.

Kanban

看板 tool

A physical card or signal that authorizes the production or movement of a specific part in a specific quantity — the operational mechanism that makes Just-in-Time possible on the shop floor.

Kata

method

Structured practice routines for developing scientific thinking habits — repeating a pattern of grasping the current condition, establishing a target condition, experimenting, and reflecting until the pattern becomes second nature.

Kenya Nakamura

中村健也 person

Toyota engineer and the company's first chief engineer (主査, shusa) for vehicle development (1913-1998). Nakamura led the development of the original Toyopet Crown, Corona, and Century, and created the project general manager system that became Toyota's signature approach to product development. He also built Toyota's 2,000-ton Clearing press and pioneered early gas turbine hybrid research.

Kiichiro Toyoda

豊田喜一郎 person

Son of Sakichi Toyoda, engineer, and founder of Toyota Motor Corporation (1894-1952). He conceived the just-in-time production concept, led the transition from textiles to automobiles, and built the Koromo Plant that became the birthplace of the Toyota Production System. His resignation during the 1950 labor crisis — accepting personal responsibility for layoffs — established a leadership ethic that still defines Toyota.

M

Material and Information Flow Analysis

モノと情報の流れ図 method

Toyota's original method for diagramming the complete flow of materials and information through a production system — the practice that was later popularized outside Toyota as "value stream mapping" by the Lean Enterprise Institute.

Mizusumashi

水すまし tool

A dedicated material delivery person who follows a fixed route on a timed cycle, supplying parts and materials to production operators so they never have to leave their stations — named after the water beetle that moves quickly across the surface.

Monozukuri

モノづくり concept

A Japanese concept encompassing the total process of making things with skill, care, and dedication — not just manufacturing technique but the spirit, pride, and craftsmanship that goes into creating excellent products.

Motion

動作のムダ concept

One of the 7 Wastes — unnecessary movement by operators during work: walking, reaching, bending, turning, searching for tools or parts. Rooted in the Gilbreths' motion study tradition and their 17 therbligs, this waste targets human movements that do not directly transform the product.

Muda

ムダ(無駄) concept

Any activity that consumes resources without creating value for the customer. At Toyota, muda is one of three interrelated categories — alongside mura (unevenness) and muri (overburden) — that define the targets for elimination in TPS.

Mura

ムラ(斑) concept

Unevenness or irregularity in workload, volume, or pace — the fluctuations that create alternating periods of overburden and waste. At Toyota, mura is often the root cause that must be addressed before muda (waste) and muri (overburden) can be sustainably eliminated.

Muri

ムリ(無理) concept

Overburden or strain placed on people, machines, or processes beyond their reasonable capacity — leading to breakdowns, safety problems, quality defects, and burnout. At Toyota, muri is one of three interrelated categories of loss alongside muda (waste) and mura (unevenness).

O

Obeya

大部屋 method

A dedicated physical room where cross-functional team members gather to manage a project or program — making status, problems, and decisions visible on the walls so that alignment and rapid problem-solving happen face-to-face.

One-Piece Flow

一個流し concept

The ideal state of flow production where each unit is processed and passed to the next operation one at a time, with no batching or WIP accumulation between steps.

One-Point Lesson

ワンポイントレッスン tool

A single-page visual teaching document focused on exactly one topic — one quality check, one safety point, one operating procedure — designed to be created quickly and used for brief, focused training at the workstation.

Operation Drawing

工作図 tool

Toyota's shop floor drawing documenting the stock removal, dimensions, tolerances, datum locations, and clamping details for each individual machining operation — the critical intermediate reference that makes plan-vs-actual comparison possible at every step in a machining line.

Over-Processing

加工そのもののムダ concept

One of the 7 Wastes — performing work beyond what the customer requires or what the product specification demands. This includes using overly precise equipment, adding unnecessary finishes, conducting redundant inspections, or processing materials in ways that add cost without adding value.

Overproduction

作りすぎのムダ concept

The most critical of the 7 Wastes — producing more, sooner, or faster than the next process requires. Uniquely emphasized by Taiichi Ohno as the root waste that generates all others: excess inventory, unnecessary transport, hidden defects, and idle waiting.

Ownership Maintenance

自主保全 tool

The second pillar of Toyota's 3 Pillar Activity — operators clean, inspect, and check their own equipment daily to detect small defects early and prevent breakdowns, taking ownership of equipment condition rather than leaving all maintenance to specialists.

P

Pareto Chart

パレート図 tool

One of the 7 QC Tools — a bar chart that ranks problem categories by frequency or impact in descending order, with a cumulative percentage line, to identify the "vital few" causes that account for the majority of a problem. Based on the Pareto principle introduced to Japan by Joseph Juran.

PDCA

PDCAサイクル method

The foundational iterative cycle for improvement and problem solving — Plan a change, Do (implement) it, Check the results, Act to standardize or adjust. Brought to Japan by W. Edwards Deming in 1950 and deeply embedded in Toyota's management system as the thinking discipline behind all improvement.

Poka-Yoke

ポカヨケ tool

A device or mechanism that either prevents a human error from occurring or detects it immediately after it happens, making it impossible for defects to flow to the next process. Originally called "baka-yoke" (fool-proofing), the name was changed after a worker objected to the implication.

Practical Problem Solving

問題解決 method

A structured PDCA-based method for investigating problems where the problem itself is clear but the root cause is unknown — scrap issues, recurring defects, equipment reliability gaps. PPS follows the same 8-step logic as Toyota Business Practice (TBP) and was the earlier name for this process before TBP was formally adopted around 2005.

Process Capacity Sheet

工程別能力表 tool

A calculation form that determines the production capacity of each machine or process in a line — including manual time, machine time, and tool change allowances — to identify the bottleneck process and establish whether the line can meet takt time.

Process Control Board

工程管理板 tool

A whiteboard at each production area that tracks planned versus actual output hour by hour, making production status and problems visible in real time so leaders can respond immediately.

Production Instruction Kanban

仕掛けかんばん tool

A specific type of kanban card that authorizes a process to produce a defined quantity of a specific part — the "make" signal in Toyota's pull system, as distinct from the withdrawal kanban that authorizes movement.

Pull System

引き取り concept

A production control method where downstream processes withdraw only what they need from upstream processes, using consumption as the signal to replenish — the opposite of forecast-driven push production.

S

Sakichi Toyoda

豊田佐吉 person

Inventor, industrialist, and founder of the Toyota industrial group (1867-1930). His automatic loom innovations — particularly devices that stopped the machine when a thread broke — gave birth to jidoka (autonomation), one of the two pillars of the Toyota Production System. The sale of his loom patents to Platt Brothers of England provided the seed capital for Toyota Motor Corporation.

Scatter Diagram

散布図 tool

One of the 7 QC Tools — a plot of paired data points on an X-Y axis that reveals whether two variables are related. Used to test hypotheses about cause-and-effect relationships identified during fishbone analysis — for example, whether furnace temperature correlates with hardness defects.

Shadow Board

影板 tool

A tool storage board with painted outlines (shadows) showing the designated location of each tool — making it instantly visible when a tool is missing, out of place, or not returned.

Shigeo Shingo

新郷重夫 person

Japanese industrial engineer (1909-1990) who taught productivity improvement courses at Toyota for roughly 30 years and authored influential books on manufacturing methodology including SMED and poka-yoke.

Shotaro Kamiya

神谷正太郎 person

Sales executive and businessman (1898-1980). Founding president of Toyota Motor Sales Co., Ltd. and the architect of Toyota's nationwide dealer network. Known as the "God of Sales" (販売の神様), Kamiya established the customer-first philosophy and multi-channel distribution system that made Toyota's commercial success possible. His famous dictum -- "Customers first, dealers second, manufacturer last" -- became a foundational principle of Toyota's business culture and complemented the production-side innovations of the Toyota Production System.

Signal Kanban

三角かんばん tool

A triangular-shaped kanban used for batch processes (such as stamping or molding) where one-piece flow is not feasible — it signals the process to produce a batch when inventory in the supermarket drops to a calculated reorder point.

Skills Matrix

力量表 tool

A visual grid showing each operator's qualification level for each process in a work area — making it immediately clear who can do what, where training gaps exist, and how flexible the team is for rotation and coverage.

SMED

シングル段取り tool

A systematic method for reducing equipment changeover time to single-digit minutes (under 10 minutes) — enabling smaller production lot sizes, more frequent changeovers, and greater production flexibility.

Spaghetti Diagram

動線図 tool

A diagram drawn on a floor plan that traces the actual movement path of an operator, material, or document through a process — revealing wasted motion and unnecessary transport that are invisible in standard process documentation.

SPC (Statistical Process Control)

統計的工程管理 method

The use of statistical methods — particularly control charts — to monitor process stability, distinguish between common-cause and special-cause variation, and maintain processes in a state of statistical control so that quality is built into the process rather than inspected after the fact.

Stability

安定 concept

The prerequisite foundation of the TPS House — the condition where the 4Ms (Man, Machine, Material, Method) are sufficiently reliable and consistent that flow, pull, and continuous improvement can function. Without stability, advanced TPS techniques collapse.

Standard Work

標準作業 concept

The currently agreed-upon best method for performing a task — defined by takt time, work sequence, and standard in-process stock. Standard work is not fixed forever; it is the baseline from which improvement begins.

Standardized Work Chart

標準作業票 tool

A visual shop floor document that defines the three elements of standardized work for a given process: takt time, work sequence, and standard in-process stock. Includes a floor layout diagram showing the operator path through the work cycle.

Standardized Work Combination Table

標準作業組合せ票 tool

A time-study chart that maps the detailed relationship between an operator's manual work time, walking time, and machine automatic cycle time across a full work cycle — used to design multi-machine operations where one operator runs several processes within takt time.

Static Accuracy Sheet

静的精度表 tool

The machine tool precision record submitted after run-off and process capability qualification — documenting spindle run-out, axis travel accuracy, and other static measurements that establish the machine's baseline condition independent of material, tooling, and cutting conditions.

Supermarket

スーパーマーケット tool

A controlled inventory buffer between two processes where each item has a defined location and quantity — the downstream process withdraws what it needs, and the withdrawal triggers replenishment from the upstream process, implementing pull at the point where continuous flow is not possible.

T

Taiichi Ohno

大野耐一 person

Production engineer and executive at Toyota Motor Corporation (1912-1990). Universally recognized as the principal architect of the Toyota Production System (TPS). Over roughly two decades from the late 1940s through the 1960s, Ohno developed the integrated system of just-in-time production, kanban, continuous flow, multiprocess handling, and waste elimination that transformed Toyota and, eventually, global manufacturing. His 1978 book Toyota Production System: Beyond Large-Scale Production remains the foundational text on TPS.

Takt Time

タクトタイム tool

The rate of customer demand expressed as a time interval — how often the customer needs one unit. Takt time is the heartbeat of a lean production system, synchronizing every process to the pace of actual demand.

Takt Time Display

タクトタイム表示 tool

An overhead or line-side display that shows the takt time, elapsed time in the current cycle, and production count — making the pace of production visible to everyone on the line so operators and leaders can see immediately whether the process is on pace.

Tatsuo Hasegawa

長谷川龍雄 person

Aeronautical engineer turned Toyota chief engineer (1916-2008). Hasegawa served as sub-chief under Kenya Nakamura on the first Toyopet Crown, then led development of the Publica, Sports 800, Corolla, Celica, and Carina as chief engineer (shusa). He codified the chief engineer system into a scalable organizational practice, introduced target costing (genka kikaku) to Toyota product development, and established the Product Planning Office in 1965.

TBP (Toyota Business Practice)

トヨタ・ビジネス・プラクティス method

Toyota's formal 8-step problem-solving method, codified in 2001 as the standardized approach for all Toyota employees worldwide. TBP is PDCA made explicit in eight structured steps, designed to develop scientific thinking capability across the organization.

Tooling Layout Drawing

刃具配置図 tool

Toyota's shop floor diagram specifying the tooling manufacturer, tool number, dimensions, and placement for each position on a machine — the reference standard for verifying that the correct tools with the correct specifications are installed correctly.

Toyota Way

トヨタウェイ concept

Toyota's codification of its management philosophy, built on two pillars — Continuous Improvement and Respect for People — first formalized in an internal document in 2001 by Fujio Cho to preserve and transmit the company's values as it globalized.

TPM (Total Productive Maintenance)

全員参加の生産保全 tool

A comprehensive equipment management system that involves all employees — especially production operators — in maintaining equipment to achieve zero breakdowns, zero defects, and zero accidents, moving beyond reactive repair to proactive care.

TPS House

TPS の家 concept

The structural diagram representing the Toyota Production System as a house — with Just-in-Time and Jidoka as the two pillars, stability as the foundation, and the goal of highest quality, lowest cost, and shortest lead time as the roof.

Transport

運搬のムダ concept

One of the 7 Wastes — the unnecessary movement of materials, parts, or products between processes. Every time material is picked up, moved, set down, or handled without being transformed, that movement is pure waste. Transport adds cost and time but never adds value.

True North

真北 concept

The ideal state that guides the direction of all improvement — zero defects, zero breakdowns, zero inventory, zero accidents, 100% value-adding activity. True North is deliberately unattainable, serving as a permanent compass heading rather than an achievable target.