Glossary of Lean and Related Terms

This glossary of terms used in quality, Six Sigma, ISO, and Lean was developed from many sources specifically for the use of Continuous Improvement Conference attendees. 

ANDON

A “Visual Control” device that indicates the “Status” of a machine, line, or process. Frequently audible alarms or warning messages accompany Andon status lights as a secondary method of communicating a problem has arisen. Andons are typically color-coded with these generic colors:
– Green (normal operations)
– Yellow (it is time for a changeover or planned maintenance)
– Red (a problem has occurred, the machine or line is “down,” and “urgent” attention is needed)

Attribute

Qualitative data that can be counted for recording and analysis. These include characteristics of occurrence, or number of times/parts installed per cycle, etc.

Auditee

Personnel responsible for area or activity being audited.

Batch Reduction

A philosophy that rejects batch, lot, or mass processing as wasteful. Product should move (flow) from operation to operation only when it is needed, in the smallest increment, one piece being the ultimate.

Black Belt

Leaders of teams responsible for measuring, analyzing, improving, and controlling key processes that influence customer satisfaction and/or productivity growth. Black belts are full-time positions.

Blitz

A blitz is a fast and focused process for improving some component of business: a product line, a machine, or a process. It utilizes a cross-functional team of employees for a quick problem-solving exercise, where they focus on designing solutions to meet some well-defined goals.

Bottleneck

The slowest operation (choke point) in a manufacturing process. Do not confuse this with a company’s “constraint” taken from TOC (Theory of Constraints), which is the slowest operation in an entire manufacturing system that, if remedied, would increase overall company throughput.

Calibrations

Comparison of a measurement standard or instrument of known accuracy with another instrument to detect, correlate, report, or eliminate by adjustment any variation in the accuracy of the item being compared.

Corrective Action Request (CAR)

A form used in internal auditing to notify a department of non-conformances in a quality system.

Catch-Ball

A series of discussion between managers and their employees during which data, ideas, and analysis are thrown like a ball. This opens productive dialogue throughout the entire company.

Cause and Effect Diagram

A problem-solving tool that graphically illustrates the relationships between various process elements which prepares problem solvers to assess the impact of variation from a standard.

Cellular Manufacturing

Generally a horseshoe or U-Shaped work area layout that enables workers to easily move from one process to another in close proximity and pass parts between workers with little effort. “Cells” typically focus on the production of specific models in "part families," but can be adjusted to many different products as needed.

Common Cause

A source of variation that is always present; part of the random variation inherent in the process itself. Its origin can usually be traced to an element of the system which only management can correct..

Constraint

Taken from the theory of constraints (TOC), a constraint is anything that limits a system from achieving higher performance versus its goal.

Continuous Flow

The link of manual and machine operations into the most efficient combinations to maximize value-added content while minimizing waste.

Control Chart

A graphic representation of a characteristic of a process, showing plotted values of some statistic gathered from that characteristic, along with one or two control limits. It has two basic uses: as a judgment to determine if a process was in control, and as an aid in achieving and maintaining statistical control.

Control Limit

A line (or lines) on a control chart used as a basis for judging the significance of the variation from subgroup to subgroup. Variation beyond a control limit is evidence that special causes are affecting the process. Control limits are calculated from process data and are not to be confused with engineering specifications.

Corrective Action

Measures taken to resolve a detected nonconformance within a product, service, or quality management system and those measures taken by management to prevent its recurrence.

CTQ: Critical To Quality

The element of a process or practice which has a direct impact on its perceived quality.

Cycle Time

The time it takes to do one repetition of any particular task typically measured from “start to start,” the starting point of one product’s processing in a specified machine or operation until the start of another similar product's processing in the same machine or process. Cycle time is commonly categorized into:
1) Manual Cycle Time: The time loading, unloading, flipping/turning parts, adding components to parts while still in the same machine/process etc.
2) Machine Cycle Time: The processing time of the machine working on a part.
3) Auto Cycle Time: The time a machine runs un-aided (automatically) without manual intervention.
4) Overall Cycle Time: The complete time it takes to produce a single unit. This term is generally used when speaking of a single machine or process.
5) Total Cycle Time: This includes all machines, processes, and classes of cycle time through which a product must pass to become a finished product. This is not Lead Time, but it does help in determining it.

Dashboard

A set of metrics, usually not more than five or six, that provides an “at-a-glance” summary of an organization’s or project’s status. Every participant in an organization/project—from the CEO to a factory floor worker—can have his or her own dashboard with function- and level-appropriate data summaries.

Design For Six Sigma (DFSS)

DFSS is a systematic methodology utilizing tools, training, and measurements to enable companies to design products and processes that meet customer expectations and can be produced at Six Sigma quality levels.

Desk Audit

An audit which is conducted of documentation only. These determine that all elements of the quality system are documented and compliant with the requirements of ISO 9001, but do not address implementation.

Detection

Detection or inspection is a part-oriented strategy that attempts to identify unacceptable output after it has been produced and to separate it from the good output.

Distribution

A distribution describes a population from which observations are drawn, categorized into cells and forming identifiable patterns. It is based on the concept of variation that states that anything measured repeatedly will arrive at different results. These results will fall into statistically predictable patterns. A bell-shaped curve (or normal distribution) is an example in which the greatest number of observations fall in the center with fewer and fewer observations falling evenly on either side of the average.

Distributions

The tendency of large numbers of observations to group themselves around some central value with a certain amount of variation or “scatter” on either side.

DMAIC

A Six Sigma structured problem solving methodology: define, measure, analyze, improve, and control.

Document Control

Activities which ensure that the review, approval, issuance, amendment, retrieval, storage, and destruction of documentation and data are performed, providing recipients with only approved documents of the latest revision at all locations where they apply. 

Enterprise Resources Planning (ERP)

Taking the needs of an entire organization into account, ERP is essentially an extension of “MRP” “Manufacturing Resources Planning” which attempts to ascertain needs and abilities of a company system.

Error & Mistake-Proofing (a.k.a. Poka-Yoke)

A Lean tool for making products correctly the first time.

External Customer

People or organizations who receive and pay for a product, a service, or information.

Failure Modes & Effects Analysis (FMEA)

A systematic/structured approach for determining the seriousness of potential failures and for identifying the sources of each potential failure. The goal of FMEA is to identify potential failures and implement corrective actions to prevent failures from occurring. “PFMEA” focuses on identifying and remediating process failures.

5S

A method of workplace organization and visual controls developed by Hiroyuki Hirano.

Japanese "S"	American "S"
Seiri (Organization)	Sort
Seiton (Tidiness)	Set in order
Seiso (Purity)	Shine
Seiketso (Cleanliness)	Standardize
Shitsuke (Discipline)	Sustain

Flow

A main objective of the Lean production effort, and one of the important concepts that passed directly from Henry Ford to Toyota. Ford recognized that, ideally, production should flow continuously all the way from raw material to the customer and envisioned realizing that ideal through a production system that acted as one long conveyor.

Force Field Analysis

A technique developed by Kurt Lewin that displays the driving (positive) and restraining (negative) forces surrounding any change. This is displayed in a “balanced sheet” format.

Frequency Distribution

A statistical table that presents a large volume of data in such a way that the central tendency (average/mean/median) and distribution are clearly displayed.

Gage R&R (Gage Repeatability and Reproducibility)

This is a statistical tool that measures the amount of variation in the measurement system from the device used, the people taking the measurement, the interaction between the device and the person, and the error seen from the parts.

Green Belt

Similar to Black Belt, but not a full-time position.

Heijunka

A method of leveling production at the final assembly line that makes just-in-time production possible. This involves averaging both the volume and sequence of different model types on a mixed-model production line.

Hosin Planning (HP)

Also known as Management by Policy or Policy Deployment. This is a means by which goals are established and measures are created to ensure progress toward those goals. HP keeps activities at all levels of the company aligned with its overarching strategic plans. HP typically begins with the “visioning process,” which addresses the key questions: Where do you want to be in the future? How do want to get there? When do you want to achieve your goal? And who will be involved in achieving the goals? HP then systematically explores the whats, whos, and hows throughout the entire organization.

Inspection, Measuring And Test Equipment

All equipment used to measure, gauge, test, inspect, or otherwise examine items to determine compliance with specifications.

Internal Customers

Employees or departments who receive output in the form of a product, a service, or information from other employees or departments within the organization. 

Internal Quality Audit

A documented activity performed to verify, by examination of objective evidence, that applicable elements of the quality system are suitable and have been developed, documented, and effectively implemented in accordance with specified requirements.

International Organization For Standardization (ISO)

This organization was formed in 1946 in Geneva, Switzerland. ISO comes from the Greek word “isos” which means to be “the same.”  It is a voluntary system that holds all companies to the same standards and must be certified by a third party.

ISO 9001:2000

The latest revision of the ISO standards.

Just-In-Time (JIT)

JIT is a system for producing and delivering the right items at the right time, in the right amounts. The key elements of JIT are flow, pull, standard work, and takt time. Principles that are fundamental to time-based competition include­ waste elimination, process simplification, set-up and batch-size reduction, parallel processing, and layout redesign. organization.

Kaizen

Continuous improvement through incremental improvement. The whole secret to Kaizen is to create an atmosphere, a culture of continuous improvement, by focusing people on problems. Kaizen complements the other tools of Lean, and it is part of a whole rather than a stand-alone process.

KAI (to modify, to change) + ZEN (think, make good, make better) = KAIZEN

Kanban

A pull material replenishment system, based on the principle that material is pulled through the production process based on actual usage of material. Kanban uses visual signals, usually a card, to move material through the value chain.

Lead Time

The time that is required from receipt of order until shipped to the customer.

Lower Control Limit

A horizontal dotted line plotted on a control chart which represents the lower process limit capabilities of a process.

Malcolm Baldrige National Quality Award

The national quality award program in the United States that recognizes companies for their management system and gives feedback for improvement opportunities.

Master Black Belt

Master Black Belts are first and foremost teachers. They also review and mentor Black Belts. The selection criteria for Master Black Belts are quantitative skills and the ability to teach and mentor. Master Black Belts are full-time positions.

Muda

The Japanese word for waste or any activity that does not add value to the customer.

Nonconformance

Failure of product or process to comply with specified requirements. For the purposes of this document, nonconformance also refers to instances of nonconformance to ISO 9001.

Nonconformities

Specific occurrences of a condition that does not conform to specifications or other inspection standards; sometimes called discrepancies or defects. An individual nonconforming unit can have the potential for more than one nonconformity. Generally a “c” or “u” chart is used to analyze systems producing nonconformities.

Non-Value Added

Activities or actions taken that add no real value to the product or service making such activities or action a form of waste.

Normal Distribution

A continuous, symmetrical density function characterized by a bell-shaped curve, e.g., distribution of sampling averages.

One-Piece Flow

Moving the product through each operation (both in the manufacturing and in the office) as a single part, never handled in batches.

Pareto Diagram

Focuses on efforts or the problems that have the greatest potential for improvement by showing relative frequency and/or size in a descending bar graph. Based on the proven Pareto principle: 20% of the sources cause 80% of any problems.

PDCA (Plan, Do, Check, Act)

PLAN: Senior management should use the visioning process in the context of its business
Plan. Hoshin Planning (HP) translates the Business Plans to action plans, meaningful to all levels of the organization.
DO: Answer the whats, hows, and whos for the total number of tiers for your organization; remember, the fewer the number of tiers, the better. Also, this is the time to bring management together and provide them with a basic understanding of HP mechanics.
CHECK: On a periodic basis, review the measurements and note what you’ve learned that can help in the future.
ACT: Make the necessary adjustments to plans and priorities in order to ensure the success of the strategy breakthroughs.

Point-Of-Use Storage (POUS)

All material is stored where it is going to be used in the process. POUS reduces material handling requirements and makes it easier to determine raw material needs due to smaller shipments from vendors.

Poka-Yoke

A mistake-proofing device or procedure to prevent a defect during order taking or manufacturing. An order-taking example is a screen for order input developed from traditional ordering patterns that questions orders falling outside the pattern. The suspect orders are then examined, often leading to the discovery of inputting errors or buying based on misinformation. A manufacturing example is a set of photocells in parts containers along an assembly line to prevent components from progressing to the next stage with missing parts.

Population

The universe of data under investigation from which a sample will be taken.

Prevention

A future-oriented strategy that improves quality by directing analysis and action toward correcting the production process. Prevention is consistent with a philosophy of continuous or never-ending improvement.

Preventive Action

Action taken to eliminate the cause(s) of a potential nonconformity or other undesirable or unsafe situation in order to prevent occurrence.

Process

The combination of people, machine and equipment, raw materials, methods and environment that produces a given product or service.

Process Capability

The measured, built-in reproducibility or consistency of the product turned out by the process. Such a determination is made using statistical methods. The statistically determined pattern or distribution can only then be compared to specification limits to decide if a process can consistently deliver product within those parameters.

Process Failure Modes Effects Analysis (PFMEA)

Is a systemized group or activities to (a) recognize and evaluate the potential failure of a product/process and its effects, (b) identify actions which could eliminate or reduce the occurrence, (c) document the process, and (d) track changes to process incorporated to avoid potential failures.

Process Management

The cycle of continuous review, re-examination, and renewal of fundamental work processes that contribute to an organization’s performance and productivity. Itself a continual process, process management must at all times challenge a process’s fit with other processes, and may result a in radical change to work methods and practices.

Pull Production

In pull production actual customer demand drives the manufacturing process as much as possible. A system of cascading production and delivery instructions from downstream to upstream activities in which nothing is produced by the upstream supplier until the downstream customer signals a need. The rate of production for each product is equal to the rate of customer consumption.

Pull System

One of the three elements of JIT. In the pull systems, the downstream process takes the product it needs and pulls it from the producer. This customer’s pull is a signal to the producer that the product is sold. The pull system links accurate information with the process to minimize waiting and overproduction.

Push System

In contrast to the pull system, product is pushed into a process, regardless of whether it is needed. The pushed product goes into inventory, and lacking a pull signal from the customer indicating that it has been bought; more of the same product could be overproduced and put in inventory.

Quality

Term that describes the condition which exists when a product’s performance and/or characteristics satisfy the stated or implied needs of the customer.

Quality Function Deployment (QFD)

A visual decision-making procedure for multi-skilled project teams which develops a common understanding of the voice of the customer and a consensus on the final engineering specifications of the product that has the commitment of the entire team. QFD integrates the perspectives of team members from different disciplines, ensures that their efforts are focused on resolving key trade-offs in a consistent manner against measurable performance targets for the product, and deploys these decisions through successive levels of detail. The use of QFD eliminates expensive backflows and rework as projects near launch.

Quality Management

Activities which include strategic planning, allocation of resources and systematic activities for quality assurance such as planning, operations, and evaluation. These activities are the responsibility of senior management.

Quality Manual

A document that is a part of the ISO 9000 system that describes a company’s higher-level approach to the ISO standards and requirements.

Quality Policy

Policy which guides all aspects of the quality system.

Quality Records

All forms and records which exist as a result of a process and serves as evidence that the product meets the specified requirements. Records may be in the form of hard copy or electronic media.

Quality System

The organizational structure, responsibilities, procedures, processes, and resources for implementing quality management.

Quality System Documents

Quality manual, system procedures manual, work instruction manual, and forms which are used to define the manner of production where their absence would adversely affect quality.

Random Cause

A source of variation which is random. In this case, a change in the source (“trivial many” variables) will not produce a highly predictable change in the response (dependent variable), e.g., a correlation does not exist. Random variation cannot be economically eliminated from a process.

Range

A measure of variation in a set of data. It is calculated by subtracting the lowest value in the data set from the highest value in the same data set.

Root Cause Analysis

Study of the original reason for nonconformance with a process. When the root cause is removed or corrected, the nonconformance will be eliminated.

Sample

One or more individual events or measurements selected from the output of a process for the purpose of identifying characteristics and performance of the whole.

Senior Management

Owner, chief executive office, chief operating officer, president, vice president, and general manager.

Seven Wastes

The seven wastes are activities identified and categorized as non-value adding events or processes that limit profitability in a company.
First identified by Taiichi Ohno of Toyota, the “seven Wastes” are as follows: (simplified)
1. Overproduction: Making more parts than you can sell.
2. Delay: Waiting for processing, parts sitting in storage, etc.
3. Transporting Parts/Materials: Moving parts to various storage locations, from process to process, etc.
4. Over-Processing: Doing more “work” to a part than is required.
5. Inventory: Committing money and storage space to parts not sold.
6. Motion: Moving parts more than the minimum needed to complete and ship them.
7. Making Defective Parts: Creating parts that cannot be sold “as is” or that must be reworked, etc.

Sigma

The Greek letter used to designate the estimated standard deviation.

Single Minute Exchange of Dies (SMED)

A series of techniques designed for changeovers of production machinery in less than ten minutes. Obviously, the long-term objective is always zero setup, in which changeovers are instantaneous and do not interfere in any way with continuous flow.

Single-Piece Flow

A situation in which products proceed, one complete product at a time, through various operations in design, order taking, and production, without interruptions, backflows, or scrap.

Six Sigma

The goal of Six Sigma is to increase profits by eliminating variability, defects, and waste that undermine customer loyalty.
Six Sigma can be understood/perceived at three levels:

1. METRIC: 3.4 Defects Per Million Opportunities (DPMO). DPMO allows you to take complexity of product/process into account.
2. METHODOLOGY: DMAIC structured problem-solving roadmap and tools.
3. PHILOSOPHY: Reduce variation in your business and make customer-focused, data driven decisions.

Special Cause

A source of variation that is intermittent, unpredictable, unstable, sometimes called an assignable cause. Usually evident by a point beyond the control limits.

Standard Deviation

A measure of the spread of the process output or the spread of a sampling statistic from the process, denoted by the Greek letter sigma (upper case Σ, lower case σ).

Standardize Work

The documentation and application of the best practices of a manufacturing process. It may include photographs and/or drawings. It ensures that production operations are performed the same way each time. It is developed with the operators and posted at the workstation.

Statistical Control

A quantitative condition which describes a process that is free of assignable/special causes of variation, e.g., variation in the central tendency and variance. Such a condition is most often evidenced on a control chart, i.e., a control chart which displays an absence of nonrandom variation.

Statistical Process Control

The use of statistical techniques such as control charts to analyze a process or its output so as to take appropriate action to achieve and maintain a state of statistical control and to improve the capability of the process.

Strategic Planning Process

Process whereby goals are set through internal and external assessment and deployed to resources for performance and improvement activities.

Stratification

The process of classifying data into subgroups based on characteristics or categories.

Supplier

Individual or company providing products or services.

Takt

The German word for pace or rhythm. Used in Lean as the rhythm of the plant; i.e., if the customer wants a part every 30 seconds, the plant (or the Lean cell) should feel the heart beat of producing a part every 30 seconds.

Takt Time

Total available production time divided by the customer and requirement. Note: Include all planned activities such as clean-up, safety meetings, etc.
For Example:
(1)   8 Hour Shift = 480 Minutes  –  (2)  10 Minute Breaks=460
1840 Pieces/Day Customer Requirements
TAKT Time = 0.25 minutes or 15 seconds

Theory of Constraints (TOC)

A Lean management philosophy that stresses removal of constraints to increase throughput while decreasing inventory and operating expenses.

Total Productive Maintenance (TPM)

A philosophy and practice of preventing the loss of productive machine time due to:
breakdowns, minor stoppages, idling, operating at less-than-planned-for cycle times, changeovers/setups, and unacceptable quality. TPM involves everyone in identifying, monitoring, and correcting the root cause of each of these losses.

Trends

The patterns in a run chart or control chart that feature the continued rise of fall in a series of points. Like runs, attention should be paid to such patterns when they exceed a predetermined number.

Upper Control Limit

A horizontal line on a control chart (usually dotted) which represents the upper limits of process capability.

Value Package

A total package of products and services that we offer to customers.  This package includes competitive cost, excellent service, and high product quality to ensure high customer satisfaction and retention.

Value-Stream Mapping

A method to describe the flow of material and information through the production system. By graphically portraying the process, one is able to see where value is added and value is lost. The ratio of value added to total lead-time is figured by documenting the current lead-time, inventory levels, and cycle times.

Variables

Characteristics of a part which can be measured such as length, id/od, width, etc.

Variation

The inevitable difference among individual outputs of a process. The sources of variation are grouped into two major classes: common causes and special causes.

Visual Management

Systems that enable anyone to immediately assess the current status of an operation or process at a glance, regardless of their knowledge of the process. Visual displays relate information and data to employees in an area through the use of charts, graphs, and process documentation.

Waste

Defects—inspection, scrap, rework
Overproduction—making more than is required right now.
Waiting—idle time.
Transportation—moving materials around the plant.
Inventory—any supply in excess of immediate need.
Motion—people moving without adding value.
Excessive Processing—unnecessary process steps.

Work In Progress (WIP)

Product or inventory in various stages of completion throughout the plant, from raw material to completed product.

Workplace Organization (5S)

The focus of 5S activity is to organize the workplace in order to make it more productive.  After 5S, one can expect to see a place for everything, and everything in its place.

Yellow Belt

A Yellow Belt is any employee who has received introductory training in the fundamentals of Lean and/or Six Sigma . The Yellow Belt gathers data, participates in problem-solving exercises, and adds their personal experiences to the exploration process. Yellow Belts should have basic high-school-level math and reading skills.