3M: Muda, Mura, Muri
The three kinds of waste in the Toyota Production System: muda is work that adds no value for the customer, mura is unevenness in workload or flow, and muri is overburden on people or machines.
Lean manufacturing acronyms and what they stand for
The 82 acronyms you hear most in plants and CI meetings: what each one stands for, what it means in a line or two, and a link to the glossary entry, guide, template or calculator that goes deeper.
0–9
4M: Man, Machine, Material, Method
Four categories used to sort the causes of a problem, and the four kinds of change a plant tracks in change point management. A relief operator, a repaired tool, a new material lot or a revised instruction are all 4M changes.
5M: Man, Machine, Material, Method, Measurement
The 4M cause categories plus measurement, used as the bones of a fishbone diagram. Some versions use environment (mother nature) as the fifth M instead of measurement.
- Glossary: 6Ms of production
- Guide: The 6Ms of Production: A Complete Manufacturing Guide
- Free: Fishbone (Ishikawa) board
- See also: The 6 Ms of production (method guide)
5S: Sort, Set in Order, Shine, Standardize, Sustain
A five-step method for organizing a workplace so that anything missing, out of place or unsafe is obvious at a glance. The steps come from five Japanese words: seiri, seiton, seiso, seiketsu and shitsuke.
- Glossary: 5S
- Guide: 5S Methodology: A Complete Guide for Manufacturing
- Free: 5S audit checklist template, Office 5S audit checklist
- See also: 5S training presentation
5W1H: Who, What, Where, When, Why, How
Six questions used to describe a problem completely before anyone tries to solve it. 5W2H adds a second H, how much.
- Glossary: 5W1H
- Guide: 5W1H Method: Defining Problems for Root Cause Analysis
- Free: 5W1H template
6M: Man, Machine, Method, Material, Measurement, Mother Nature
Six categories for sorting the possible causes of a production problem, usually drawn as the six bones of a fishbone diagram. Working through all six keeps a team from fixing only the cause it already suspects.
- Glossary: 6Ms of production
- Guide: The 6Ms of Production: A Complete Manufacturing Guide
- Free: Fishbone (Ishikawa) board
- See also: The 6 Ms of production (method guide)
8D: Eight Disciplines
A team method for fixing a serious or repeat problem in eight steps, from forming the team and containing the problem to finding the root cause, putting permanent actions in place and preventing recurrence. Automotive customers often ask suppliers for an 8D report after a complaint.
A
AM: Autonomous Maintenance
The TPM pillar in which operators take on basic care of their own equipment, such as cleaning, inspecting, lubricating and tightening, so small problems are found before they become breakdowns. It is also called jishu hozen.
APQP: Advanced Product Quality Planning
A structured way, set out by the automotive industry group AIAG, to plan a new product and its production process in five phases so that customer requirements are met before production starts. PPAP is the approval step near the end of APQP.
AQL: Acceptance Quality Limit
The worst average defect rate a sampling plan treats as acceptable over a series of lots. It was formerly called the acceptable quality level, and together with the lot size it sets the sample size and accept and reject numbers in the standard sampling tables.
B
BBS: Behavior-Based Safety
A safety approach in which trained coworkers observe specific work behaviors, give feedback on the spot and track the results, so safe habits are reinforced before anyone gets hurt.
C
CAPA: Corrective and Preventive Action
The process for removing the cause of a problem that has happened (corrective action) and of one that could happen (preventive action), then checking the fix worked. ISO 9001 requires corrective action, and medical device rules require a full CAPA process.
CI: Continuous Improvement
The ongoing effort to make processes better through many small, regular changes made by the people who do the work, rather than occasional big projects. Kaizen is the Japanese word for it.
CILR: Clean, Inspect, Lubricate, Retighten
The four basic equipment care tasks operators do as part of autonomous maintenance, usually from a short checklist for each machine. Regular CILR catches loose bolts, leaks, contamination and wear early.
CMMS: Computerized Maintenance Management System
Software that holds a plant's asset list and maintenance history and manages work orders, preventive maintenance schedules and spare parts.
COPQ: Cost of Poor Quality
What a business spends because work is not done right the first time: scrap, rework, returns, warranty claims and complaints, and in broader definitions the inspection done to catch defects.
Cpk: Process Capability Index
A measure of how well a stable process fits inside its specification limits, taking into account how far the process average is from the center. Cp is the same comparison without the centering adjustment.
CTQ: Critical to Quality
A measurable product or process characteristic that matters most to the customer, with a target and limits. Six Sigma projects turn what customers say into CTQs so the team knows what to measure.
- Glossary: Critical to quality (CTQ)
- Free: DMAIC project charter template
D
DFMEA: Design Failure Mode and Effects Analysis
An FMEA done on a product design, before it is released, to find the ways the design could fail, rate the risk of each and change the design or add tests to reduce it.
DMADV: Define, Measure, Analyze, Design, Verify
The Six Sigma road map for designing a new product or process, where DMAIC is used to improve one that already exists. It is the core of Design for Six Sigma (DFSS).
- Glossary: Six Sigma
- Guide: What is DMAIC? A Guide to the DMAIC Process
- See also: DMAIC
DMAIC: Define, Measure, Analyze, Improve, Control
The five-phase road map Six Sigma teams use to improve an existing process: define the problem, measure how the process performs now, analyze the root causes, improve the process and control it so the gain holds.
- Glossary: DMAIC
- Guide: DMAIC Process: A Quick Guide for Beginners
- Free: DMAIC Storyboard
- See also: DMAIC training presentation
DOWNTIME: Defects, Overproduction, Waiting, Non-utilized talent, Transportation, Inventory, Motion, Extra processing
A memory aid for the eight wastes of lean: each letter is one kind of activity that uses time and resources without adding value for the customer. TIMWOODS lists the same eight wastes in a different order.
DPMO: Defects Per Million Opportunities
The number of defects for every million chances to make one, which lets processes with different numbers of possible defects per unit be compared. It converts to a sigma level; six sigma is usually quoted as 3.4 DPMO.
- Glossary: Six Sigma
- Guide: What is the Six Sigma Lean Methodology?
- Free: DPMO and sigma level calculator
E
ECR: Engineering Change Request
A formal request to change a released design, drawing, material or process, reviewed for cost, risk and effect on quality before it is approved and carried out.
EHS: Environment, Health and Safety
The function and practices that protect workers and the environment at a site: hazard and risk assessment, incident and near-miss reporting, permits and training, and compliance with safety and environmental rules. HSE and SHE mean the same thing.
EPEI: Every Part Every Interval
How often each part number comes round in a production sequence. If a machine runs every part it makes at least once every three days, its EPEI is three days; shorter changeovers allow a shorter EPEI and smaller lots.
F
FMEA: Failure Mode and Effects Analysis
A step-by-step review of how a product or process could fail, what each failure would cause and how likely it is to happen and be caught, so the biggest risks are reduced before they reach the customer.
FPY: First Pass Yield
The share of units that go through a process step right the first time, with no rework, repair or scrap, out of all the units that entered it.
FTA: Fault Tree Analysis
A top-down method that starts from one unwanted event, such as a machine failure, and breaks it into the combinations of causes that could produce it, drawn as a tree with AND and OR gates.
G
Gage R&R: Gage Repeatability and Reproducibility
A study of how much of the variation in measurements comes from the measuring system itself. Repeatability is the variation when one person measures the same part several times; reproducibility is the variation between different people.
H
HSE: Health, Safety and Environment
The same function as EHS, with the letters in a different order; HSE is the more common form in the UK, Europe and the Middle East. In Great Britain, HSE is also the name of the national regulator, the Health and Safety Executive.
J
JDI: Just Do It
A small improvement that is quick, cheap and clearly right, so it is done straight away instead of going through a full project. Many suggestion systems sort ideas into JDIs and larger kaizens.
- Glossary: Kaizen teian
- Guide: Kaizen Teian: Individual Improvement Suggestions
- Free: Just Do It (JDI) card template
JIT: Just-in-Time
Making and moving only what is needed, when it is needed, in the amount needed, so stock and lead time stay low. It is one of the two pillars of the Toyota Production System.
JSA: Job Safety Analysis
A review that breaks a job into its steps, lists the hazards in each step and records the controls that remove or reduce them, before the work starts. It is also called a job hazard analysis (JHA).
K
KPI: Key Performance Indicator
A measure a team or plant tracks to see whether it is meeting an important goal, such as OEE, first pass yield, on-time delivery or injuries. A useful KPI has a target, an owner and a set time when it is reviewed.
- Guide: Top Maintenance KPIs to Track
- Free: Maintenance KPI tracker
- See also: KPI dashboards, Leading and lagging indicators
L
LOTO: Lockout/Tagout
The procedure for shutting a machine down, isolating every energy source and locking and tagging it so it cannot start while someone is servicing it.
- Glossary: Lockout/tagout (LOTO)
- Free: Lockout/tagout (LOTO) procedure template
LPA: Layered Process Audit
Short, frequent checks that key process steps and controls are being followed, done by several layers of the organization from supervisors up to plant leaders. LPAs are common in automotive plants.
LSS: Lean Six Sigma
An approach that combines lean's focus on removing waste and speeding up flow with Six Sigma's data-driven methods for cutting variation and defects, usually run as DMAIC projects.
- Glossary: Six Sigma
- Guide: Lean Six Sigma Tools and Techniques
- Free: DPMO and sigma level calculator
LSW: Leader Standard Work
A written routine for supervisors and managers that sets what they check, where and how often, such as gemba walks, board reviews and audits, so the standards on the floor are kept up.
M
MSA: Measurement System Analysis
A set of studies that checks whether a gage, method and the people using them measure accurately and consistently enough to trust the data. Gage R&R is the most common MSA study.
MTBF: Mean Time Between Failures
The average running time between breakdowns of a repairable machine: total operating time divided by the number of failures. A rising MTBF means the machine is becoming more reliable.
MTTR: Mean Time to Repair
The average time it takes to get a failed machine working again: total repair time divided by the number of repairs. It is sometimes read as mean time to restore.
N
NCR: Non-Conformance Report
A record of a product, material or process that does not meet its requirement, with what was found, how much is affected and what will be done with it, such as rework, scrap, use as is or return to the supplier.
O
OEE: Overall Equipment Effectiveness
How much of a machine's planned production time is truly productive, calculated as availability times performance times quality. 100% means only good parts, made as fast as possible, with no stops.
OJT: On-the-Job Training
Training given at the workstation, by an experienced person, while the trainee does the real job. It works best with a written standard and a method such as TWI Job Instruction.
OpEx: Operational Excellence
Running a business so that it delivers on safety, quality, delivery and cost every day while it keeps improving. In finance, OpEx is also short for operating expenses, which is a different thing.
OPL: One-Point Lesson
A one-page training sheet that teaches a single point, such as one check, one setting or one safety rule, mostly with pictures, so it can be read in a few minutes at the workstation.
OTD: On-Time Delivery
The share of orders or order lines delivered on or before the date promised to the customer. It is a standard measure of both a plant's and a supplier's delivery performance.
- Glossary: On-time delivery (OTD)
- Free: Supplier scorecard
P
PCE: Process Cycle Efficiency
Value-added time divided by total lead time, which shows how much of the time a product spends in the process is actually spent adding value to it.
PDCA: Plan, Do, Check, Act
A four-step cycle for testing a change and learning from it: plan the change, try it on a small scale, check the results against the plan and act by adopting, adjusting or dropping it. It is also called the Deming cycle.
- Glossary: PDCA (Plan-Do-Check-Act)
- Guide: PDCA Cycle: The Foundation of Continuous Improvement
- Free: PDCA template
PdM: Predictive Maintenance
Maintenance timed by the measured condition of the equipment, such as vibration, temperature or oil analysis, so a part is repaired or replaced just before it is likely to fail.
PDSA: Plan, Do, Study, Act
W. Edwards Deming's name for the PDCA cycle. He preferred study to check, to stress learning from the results rather than only inspecting them.
- Glossary: PDCA (Plan-Do-Check-Act)
- Guide: PDCA Cycle: The Foundation of Continuous Improvement
- Free: PDCA template
PFMEA: Process Failure Mode and Effects Analysis
An FMEA done on a manufacturing or assembly process, step by step, to find how each step could fail to make a good part and what controls will prevent or detect it.
PM: Preventive Maintenance
Maintenance done on a fixed schedule, by time or by use, such as inspections, lubrication and part changes, to keep equipment from breaking down. In TPM, planned maintenance is the pillar that owns it.
PPAP: Production Part Approval Process
How a supplier, mainly in automotive, proves to its customer that its production process can make a part to every requirement at the quoted rate. The AIAG manual lists 18 elements, from design records and FMEAs to capability studies and the part submission warrant.
- Glossary: Production part approval process (PPAP)
- Free: PPAP checklist
PPM: Parts Per Million
In quality, the number of defective parts for every million made, shipped or received. Eight rejects in 10,000 parts is 800 PPM.
- Glossary: Parts per million (PPM)
- Free: Supplier scorecard
PPT: People, Process, Technology
A framework for planning a change by looking at the people who do the work, the process they follow and the technology that supports them together, because the weakest of the three limits the result. Outside this framework, PPT usually means a PowerPoint file.
R
RACI: Responsible, Accountable, Consulted, Informed
A chart that lists each task or decision against the people involved and marks who does the work, who owns the outcome, who gives input and who is kept up to date. Each task should have exactly one accountable person.
RCA: Root Cause Analysis
Finding the underlying cause of a problem, the one that will stop it coming back once fixed, instead of treating the symptom. Common tools are the 5 Whys, the fishbone diagram and fault tree analysis.
RCM: Reliability-Centered Maintenance
A structured method for choosing the right maintenance task for each way a piece of equipment can fail, based on what the failure would cost or put at risk.
RFT: Right First Time
Doing a task correctly the first time with no rework or correction, and the measure of how often that happens. It is also written FTR (first time right).
RTY: Rolled Throughput Yield
The chance that a unit passes every step of a process with no rework or scrap, found by multiplying the first pass yields of all the steps. Three steps at 95% each give an RTY of about 86%.
S
SCAR: Supplier Corrective Action Request
A formal request to a supplier to contain a quality problem it caused, find the root cause and put a permanent fix in place, often answered with an 8D report.
SIPOC: Suppliers, Inputs, Process, Outputs, Customers
A one-page, high-level map of a process that lists who supplies it, what goes in, the main steps, what comes out and who receives it. It is often done at the start of a DMAIC project to agree the scope.
- Glossary: SIPOC diagram
- Free: SIPOC board
SMART: Specific, Measurable, Achievable, Relevant, Time-bound
Five tests a well-written goal should pass. Some versions use attainable for the A and realistic for the R.
- Glossary: SMART goals
- Guide: How to Set SMART Goals for Manufacturing Excellence
- Free: SMART goals template
SMED: Single-Minute Exchange of Die
A method for cutting changeover time: do as much of the setup work as possible while the machine is still running, then simplify what is left. Single minute means a single-digit number of minutes, under ten.
SMP: Standard Maintenance Procedure
Step-by-step written instructions for a maintenance task, with the tools, parts, safety steps and checks needed, so the job is done the same safe way by whoever does it.
- Glossary: Standard maintenance procedure (SMP)
SOP: Standard Operating Procedure
A written, approved description of how a task or process must be done, so everyone does it the same correct and safe way.
SPC: Statistical Process Control
Using control charts to watch a process over time and tell normal, common cause variation from special causes that need action, so problems are caught before parts go out of specification.
SQCDP: Safety, Quality, Cost, Delivery, People
Five headings many plants use for daily tier boards and KPIs. SQDC, SQDCP and SQDCM (with morale) are the same idea with the letters in a different order or one heading changed.
- Glossary: SQDCM
- Guide: Tier Boards: Cascading Daily Management Explained
- Free: SQCDP Tier Board
T
TEEP: Total Effective Equipment Performance
How much of all calendar time, 24 hours a day and every day of the year, a machine spends making good parts at full speed. It is OEE multiplied by utilization.
- Glossary: Total effective equipment performance (TEEP)
- Free: OEE tracking sheet
TIMWOOD: Transportation, Inventory, Motion, Waiting, Overproduction, Over-processing, Defects
A memory aid for the original seven wastes of the Toyota Production System. Adding S for unused skills gives TIMWOODS, the eight wastes.
TIMWOODS: Transportation, Inventory, Motion, Waiting, Overproduction, Over-processing, Defects, Skills
A memory aid for the eight wastes of lean, where S stands for unused skills or talent. DOWNTIME lists the same eight wastes in a different order.
TOC: Theory of Constraints
A management approach that improves a whole system by finding the one constraint that limits its output and managing everything around it, using five focusing steps. It was set out by Eliyahu Goldratt.
TPM: Total Productive Maintenance
A plant-wide approach to equipment reliability in which operators, maintenance and managers share responsibility for keeping machines in top condition, aiming for no breakdowns, small stops, defects or accidents. It is usually organized in eight pillars and measured with OEE.
TPS: Toyota Production System
The production and management system developed at Toyota and the basis of what the West calls lean manufacturing. It is often drawn as a house with two pillars, just-in-time and jidoka.
TQM: Total Quality Management
A management approach in which everyone in the organization works to improve quality and customer satisfaction, using data, problem solving and continuous improvement in every department, not only in inspection.
TWI: Training Within Industry
A training program created in the United States during World War II to teach supervisors three skills: Job Instruction, Job Methods and Job Relations. Job Instruction is still widely used to teach standard work.
V
VA / NVA: Value-Added / Non-Value-Added
A way of sorting each step of a process by whether the customer would pay for it: value-added steps change the product in a way the customer wants, non-value-added steps do not. Steps that add no value but cannot be removed yet, such as required checks, are often called necessary non-value-added (NNVA).
- Glossary: Value-added time
- Guide: Value-Added vs Non-Value-Added Time in Manufacturing
- Free: Time study sheet
VSM: Value Stream Mapping
Drawing every step, wait and information flow needed to turn an order into a delivered product, so the team can see where the waste and delays are and design a better future state.
W
WCM: World Class Manufacturing
A structured production system that combines lean, TPM and quality methods and aims for zero accidents, defects, breakdowns and waste. It is built on ten technical pillars, and its hallmark is cost deployment, which puts a money value on every loss so improvement goes where the cost is highest.
WIP: Work in Process
Material that has started a production process but is not finished yet, such as parts waiting between stations; it is also called work in progress. Lean treats extra WIP as waste because it ties up cash and space, hides problems and lengthens lead time.
- Glossary: Work in process (WIP)
- Free: Lead time calculator, Lead time worksheet
Often mistaken for acronyms
These lean words are often searched as if each letter stood for something. They are ordinary Japanese or German words, plus one English one. The Japanese lean terms page gives each word in Japanese, with how to say it.
- Lean
- Lean is not an acronym. The term was coined by John Krafcik in a 1988 article to describe Toyota-style production, which uses less of everything: less inventory, space, effort and time. Lean manufacturing in the glossary
- Kaizen
- A Japanese word made from kai (change) and zen (good), usually translated as continuous improvement or change for the better. Kaizen in the glossary, Kaizen training presentation
- Gemba
- A Japanese word meaning the actual place: in lean, the shop floor or wherever the value is created. Gemba in the glossary
- Andon
- A Japanese word for a paper lantern. In lean it is the light, sound or cord an operator uses to call for help when a problem occurs. Andon in the glossary
- Kanban
- A Japanese word for a signboard or card. In lean it is the signal, often a card, that tells the previous process to make or move more parts. Kanban in the glossary
- Poka-yoke
- A Japanese term meaning mistake-proofing, from poka (an inadvertent mistake) and yokeru (to avoid). It is a device or method that stops an error happening or makes it obvious at once. Poka-yoke in the glossary, Poka-yoke (method guide)
- Takt
- A German word for a beat or pulse, as in music. Takt time is the pace of customer demand: available working time divided by the number of units the customer needs. Takt time in the glossary
FAQ
Questions about lean acronyms
Need more than the letters?
The glossary explains 218 lean terms in plain words, and the library lists every article and e-book we have published.