Industrial Engineering & Manufacturing Vocabulary: 100 Key English Terms
Industrial engineers and plant staff use English more often than they expect: customer audits, ERP screens, lean and Six Sigma training, supplier quality requirements and reports for a head office abroad are very often in English. Knowing the core vocabulary of production planning, quality, lean, work study, inventory and safety helps you run a meeting on the shop floor, explain a KPI and write a clear improvement report.
100 terms
11 topics
44 core terms
200 example sentences
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Production Planning and Control
capacity
noun
Meaning
The maximum amount a machine, line or plant can produce in a given time, for example 1,200 units per shift.
Where you use it
Used in planning meetings, budgets and customer talks. Plants add, increase or free up capacity, run at full capacity or have spare capacity. Capacity planning compares what you can make with what customers want.
Examples
We are running at 95% capacity, so we can't take another big order before March.
A third shift would add about 30% more capacity without buying new machines.
Usage note
Do not confuse capacity (how much you can make) with capability (how well a process stays within its tolerances), as in process capability.
The total time between the start of a process, such as receiving an order, and its end, such as delivering the product to the customer.
Where you use it
Used with customers, suppliers and planners. You quote, shorten or reduce a lead time, and there are different kinds: supplier lead time, production lead time, delivery lead time. Long lead times usually mean more inventory and more waiting.
Examples
The supplier's lead time for castings is eight weeks, so we have to order now.
Our goal this year is to reduce production lead time from ten days to five.
Usage note
'Lead' here rhymes with 'need' /liːd/, not with 'red' (the metal).
Common phrases
reduce lead time · supplier lead time · production lead time · long lead time · lead time of six weeks
The slowest step or resource in a process, which limits the output of the whole system, just as the neck of a bottle limits how fast liquid flows out.
Where you use it
Used in planning, improvement and capacity discussions. Teams identify, find, remove or eliminate a bottleneck, and work piles up in front of it. The Theory of Constraints says that improving anything other than the bottleneck does not raise total output.
Examples
The heat treatment furnace is our bottleneck; everything else waits for it.
Once we removed the bottleneck at welding, the problem moved to painting.
Common phrases
identify the bottleneck · remove a bottleneck · bottleneck operation · capacity bottleneck
A plan that shows which products will be made, in what quantity, on which line or machine and when, usually for the coming days or weeks.
Where you use it
Planners create, update, release and freeze the production schedule; supervisors follow it. You can be on schedule, ahead of schedule or behind schedule. Rush orders and breakdowns often force a change to the schedule.
Examples
The production schedule for next week is frozen, so new orders will start on the 14th.
We are two days behind the production schedule because of the mold repair.
Usage note
Schedule is pronounced /ˈskedʒuːl/ in American English and often /ˈʃedjuːl/ in British English.
Common phrases
weekly production schedule · freeze the schedule · behind schedule · update the production schedule
A complete list of the parts, materials and quantities needed to make one unit of a product, often arranged in levels from the final product down to raw materials. Shortened to BOM.
Where you use it
The backbone of MRP and ERP systems. Engineers create, update and release the BOM, and planners explode it to calculate material needs. BOM is said as a word, 'bom', or letter by letter. In food and chemicals it is often called a recipe or formula.
Examples
The bill of materials for this pump has 146 items on four levels.
Engineering changed the gasket, but nobody updated the bill of materials in the ERP system.
Common phrases
update the bill of materials · multi-level BOM · BOM explosion · release a BOM
Short for material requirements planning: a method, usually run in software, that uses the production plan, bill of materials and stock levels to work out what to buy or make and when.
Where you use it
Planners run MRP, often overnight, and act on the planned orders and messages it creates. MRP II (manufacturing resource planning) later added capacity and finance and grew into ERP. Wrong master data, such as an old BOM or lead time, gives wrong MRP results.
Examples
MRP suggests ordering 5,000 brackets, but half of them are already in the warehouse, so the stock data must be wrong.
We run MRP every night, so check the planned orders first thing in the morning.
Common phrases
run MRP · MRP system · MRP run · MRP planned orders
Short for enterprise resource planning: one software system that connects a company's purchasing, production, stock, sales and finance data, such as SAP.
Where you use it
Almost every plant runs on an ERP system. People enter, book or check transactions in ERP and talk about ERP implementation projects and go-live dates. Turkish teams also use the abbreviation ERP in daily speech.
Examples
Please book the scrap in the ERP system before the end of the shift.
The new ERP goes live in January, so all planners will be trained in December.
Common phrases
ERP system · ERP implementation · enter in ERP · ERP go-live
An estimate of how many units customers will order in future periods, based on past sales, customer plans and market information.
Where you use it
The starting point of production and capacity planning. Sales and planning prepare, update and review the forecast, which may turn out too high or too low. Forecast accuracy is measured and discussed every month, often in S&OP meetings.
Examples
The demand forecast for the summer models is 20% higher than last year.
Our customer changed their demand forecast three times this month, which makes planning very hard.
Common phrases
rolling demand forecast · forecast accuracy · update the forecast · monthly demand forecast
Dividing the tasks on a production line among the workstations so that each station has about the same amount of work and none is over takt time.
Where you use it
Done when a line is designed or demand changes. Engineers balance or rebalance a line, often with a yamazumi chart (a stacked bar chart of work per station). The minimum number of stations is the total work content divided by takt time, rounded up.
Examples
After line balancing, we run the same volume with seven operators instead of nine.
We need to do the line balancing again because takt time changes in April.
Common phrases
line balancing study · rebalance the line · yamazumi chart · line balancing efficiency
A plan that states how many of each finished product will be made in each period, usually week by week, and drives material and capacity planning. Shortened to MPS.
Where you use it
Sits between the sales and operations plan and MRP. Planners build, load and freeze the MPS; inside the frozen zone at the start, nothing changes without approval. MRP uses the MPS and the bill of materials to calculate part needs.
Examples
The master production schedule is frozen for the next two weeks.
Sales wants to add 500 units to the master production schedule for week 12.
Common phrases
freeze the master production schedule · MPS frozen zone · load the MPS · master scheduling
Describing a production strategy in which products are made only after a customer places an order, rather than in advance for stock. Shortened to MTO.
Where you use it
Contrasted with make-to-stock (MTS), where products are made in advance from a forecast, and with engineer-to-order (ETO) and assemble-to-order (ATO). Make-to-order means little finished goods stock but longer lead times for customers.
Examples
Our industrial ovens are make-to-order, so the lead time is about ten weeks.
We moved the low-volume models to make-to-order to cut finished goods stock.
Common phrases
make-to-order production · make-to-stock · assemble-to-order · engineer-to-order · MTO business
To increase production step by step, for example after a new product launch or the start of a new line, until the planned volume is reached.
Where you use it
Very common in project and launch meetings. You ramp up production, a line or a supplier. The noun is written with a hyphen, 'ramp-up': the ramp-up phase, a ramp-up curve. The opposite is 'ramp down'.
Examples
We plan to ramp up to 400 vehicles a day by the end of the second quarter.
The supplier is struggling to ramp up, so we may have shortages in June.
Common phrases
ramp up production · ramp-up phase · ramp up to full capacity · ramp-up curve
A set of machines and workstations arranged in order, where a product moves from one step to the next until it is finished.
Where you use it
One of the most common words in any factory. Lines are usually numbered or named (Line 2, the packaging line), and people talk about starting, stopping, running and balancing a line. In daily speech it is often shortened to 'the line'.
Examples
Production line 3 was down for two hours this morning because of a conveyor fault.
We are adding a second production line to meet the new customer's volumes.
Common phrases
run a production line · stop the production line · production line layout · set up a new production line
A production line where parts are added to a product step by step, with each worker or robot doing one fixed task, as in car and appliance plants.
Where you use it
Used for any line where things are put together rather than shaped or machined. Henry Ford's moving assembly line of 1913 is the classic example. People work on the assembly line, and a stopped line is very expensive, so problems are escalated quickly.
Examples
She started on the assembly line and is now a team leader on the night shift.
Each station on the assembly line has 58 seconds to finish its tasks.
Usage note
Here 'assembly' means putting parts together, not a meeting. 'Montage line' is not used in English; say 'assembly line'.
Common phrases
work on the assembly line · moving assembly line · final assembly line · stop the assembly line
One place on a line or in a work area where a worker or machine carries out a set group of tasks, with the tools and parts needed for them.
Where you use it
Common in line balancing, layout and ergonomics work. Engineers design, number and balance workstations, and assign tasks to them. In offices the word can also mean a desk with a computer, so the context decides.
Examples
Workstation 4 is overloaded, so we moved the labeling task to workstation 5.
Every workstation should have its parts within easy reach of the operator.
Common phrases
workstation design · assign tasks to a workstation · manual workstation · bottleneck workstation
The number of good units a process, line or plant actually produces in a period of time, such as parts per hour.
Where you use it
A key word in performance reviews and improvement projects. Teams increase, improve or measure throughput, and a bottleneck limits it. Capacity is what is possible; throughput is what really comes out.
Examples
After the new fixture was installed, throughput went up from 85 to 110 parts per hour.
The paint shop is the bottleneck, so it sets the throughput of the whole plant.
Time when a machine or line is not producing even though it is scheduled to, because of a breakdown, a changeover, missing material or another problem.
Where you use it
One of the most tracked numbers on the shop floor. Teams record, log, track and reduce downtime, and separate planned downtime (maintenance, breaks) from unplanned downtime (breakdowns). Reasons are usually coded so they can be analyzed.
Examples
We had 3.5 hours of unplanned downtime on the press line last week.
Please log every stop longer than five minutes on the downtime sheet.
Usage note
Downtime is uncountable: say 'two hours of downtime', not 'two downtimes'.
One of the fixed working periods into which a day is divided in a plant, such as 07:00–15:00, and also the group of people who work in that period.
Where you use it
Used every day in planning and handovers. People work the night shift or are on the morning shift; plants run two or three shifts. A shift handover is the short meeting or report passed to the next team.
Examples
We run three eight-hour shifts, five days a week.
The night shift reported a leak on the hydraulic unit during the shift handover.
Usage note
English usually says 'on' a shift: 'I'm on the night shift this week' sounds more natural than 'in the night shift'.
Common phrases
night shift · shift handover · work three shifts · shift supervisor · on the morning shift
Short for overall equipment effectiveness: a percentage that shows how well a machine is used, calculated as availability × performance × quality.
Where you use it
One of the main KPIs in manufacturing, shown on boards and dashboards. Teams measure, track and improve OEE. The three factors show where losses come from: stops, slow running or defects. A figure of 85% is often quoted as world class.
Examples
OEE on line 2 was 64% last month: availability 80%, performance 90%, quality 89%.
The main reason for our low OEE is long changeovers.
A group of identical products made together in one production run, often with one batch number so it can be traced later.
Where you use it
Used in production, quality and traceability. Plants produce in batches, and quality releases, holds or rejects a batch. Batch size is a key planning choice: large batches mean fewer changeovers but more inventory. 'Lot' is used in a very similar way.
Examples
Batch 4471 is on hold until the lab results come back.
We reduced the batch size from 2,000 to 500 pieces after shortening the changeover.
Common phrases
batch size · batch number · release a batch · batch production · in batches
The time needed to prepare a machine or line to produce a different product, from the last good part of one job to the first good part of the next.
Where you use it
Closely linked to changeover, the act of switching products. Teams measure and reduce setup time because it is lost production, and it decides how small batches can be. SMED is the best-known method for cutting it.
Examples
Setup time on the press is 90 minutes, so the planners run very large batches.
Preparing the next die while the machine is still running cut our setup time to 25 minutes.
Usage note
'Setup' (one word) is the noun; 'set up' (two words) is the verb: 'We set up the machine; the setup took an hour.'
Common phrases
reduce setup time · long setup time · setup and changeover · setup time per batch
Planned maintenance done at regular intervals, such as cleaning, lubricating and replacing worn parts, to stop breakdowns before they happen. Often shortened to PM.
Where you use it
Maintenance teams schedule and carry out preventive maintenance based on time (every month) or usage (every 500 hours). It is contrasted with breakdown maintenance and with predictive maintenance, which uses sensor data. British English also says 'preventative'.
Examples
Line 1 will be down on Saturday morning for preventive maintenance.
Since we started a proper preventive maintenance plan, breakdowns on the compressors have almost stopped.
Common phrases
preventive maintenance plan · scheduled preventive maintenance · carry out preventive maintenance · PM schedule
The arrangement of machines, workstations, storage areas and aisles inside a factory, planned to keep material flow short, safe and simple.
Where you use it
A classic industrial engineering subject, also called facility layout. Layouts are often described as process layout (similar machines grouped together), product layout (machines in the order of operations) or cellular layout. Engineers draw and change layouts, often using spaghetti diagrams to show walking paths.
Examples
The new plant layout puts goods receiving next to the first operation and saves 400 meters of forklift travel an hour.
We will move to a cellular plant layout for the valve product family.
The percentage of available time that a machine, person or plant is actually busy working.
Where you use it
Used in capacity planning and cost discussions. Plants report capacity utilization, and managers like high machine utilization. Lean warns that running every machine flat out without demand only builds inventory, and queueing theory shows that waiting times grow fast as utilization nears 100%.
Examples
Utilization of the CNC machines is only 55% because of the long setups.
Capacity utilization in the industry fell to 74% this quarter.
Usage note
British English writes 'utilisation'. Utilization is not the same as OEE: a machine can be busy but running slowly or making scrap.
Short for total productive maintenance: an approach in which operators and maintenance staff share responsibility for keeping equipment in top condition, aiming for no breakdowns, defects or accidents.
Where you use it
Developed in Japan and spread by Seiichi Nakajima. It is built on pillars such as autonomous maintenance (operators clean, inspect and lubricate their own machines), planned maintenance and focused improvement. OEE is its main measure.
Examples
As part of TPM, operators now do a ten-minute cleaning and inspection at the start of each shift.
Our TPM program has cut breakdowns on the bottling line by half.
A way of running production that aims to deliver what the customer needs with the least waste of time, material and effort, based on the Toyota Production System.
Where you use it
Used in strategy, training and improvement work. Companies implement or adopt lean manufacturing, and people often just say 'lean' (a lean project, lean tools, going lean). The term was made popular by the 1990 book 'The Machine That Changed the World'.
Examples
Since we started lean manufacturing, the floor space used for inventory has dropped by a third.
All new supervisors take a two-day course in lean manufacturing.
In lean thinking, any activity that uses time or resources but adds no value for the customer, such as waiting, extra movement or making too much.
Where you use it
Lean teams identify, eliminate and reduce waste. The classic list has seven wastes: transport, inventory, motion, waiting, overproduction, overprocessing and defects; many add an eighth, unused skills. The Japanese word muda is also common.
Examples
Walking 200 meters to get parts is waste; let's bring the rack to the line.
During the gemba walk we found waste in almost every step of the packing process.
Usage note
In lean, waste means 'israf', not 'atık' (garbage). English uses the same word for both, so watch the context.
The pace at which you must finish one product to meet customer demand: the available working time divided by the number of units the customer needs.
Where you use it
Used to design lines and set the rhythm of work. If a shift has 27,000 seconds of working time and the customer needs 450 units, takt time is 60 seconds. Stations should finish their work within takt time. The word comes from German 'Takt' (beat, rhythm).
Examples
With the new order volumes, takt time drops from 60 to 48 seconds.
Station 6 is over takt time, so the line can't keep up with demand.
Usage note
Takt time comes from customer demand, cycle time from the process. If cycle time is longer than takt time, you cannot meet demand.
Common phrases
calculate takt time · meet takt time · over takt time · takt time of 60 seconds
A workplace organization method with five steps: sort, set in order, shine, standardize and sustain. It keeps work areas clean, tidy and easy to manage.
Where you use it
Often the first lean tool a plant introduces. Teams implement 5S in an area, run 5S audits and post scores on boards. The steps come from Japanese words starting with S (seiri, seiton, seiso, seiketsu, shitsuke). Some companies add safety as a sixth S.
Examples
After the 5S project, every tool in the maintenance workshop has a marked place on the shadow board.
Our 5S audit score in the warehouse went from 52 to 81 in three months.
Usage note
Say it 'five S'. The English names of the steps vary between companies (for example 'sweep' instead of 'shine'), but the idea is the same.
A lean method of drawing all the steps, material flows and information flows needed to make a product, to see where time is lost and plan improvements. Often shortened to VSM.
Where you use it
Teams draw a current-state map and then a future-state map, using standard symbols for processes, inventory and data boxes. The map usually shows that value-added time is a tiny part of total lead time. It is done by walking the real process, not from the office.
Examples
Value stream mapping showed that the product spends 11 days in the plant but is worked on for only 40 minutes.
We'll start the project with a value stream mapping workshop next Tuesday.
Common phrases
value stream mapping workshop · current-state map · future-state map · draw a value stream map
A production approach in which materials and parts arrive exactly when they are needed and in the quantity needed, so very little inventory is kept. Often shortened to JIT.
Where you use it
One of the two main pillars of the Toyota Production System. Used as a noun (move to just-in-time) and as an adjective (just-in-time delivery). JIT needs reliable suppliers and stable processes, and supply disruptions show its risks.
Examples
Seats are delivered just-in-time, in the same sequence as the cars on the line.
Just-in-time is hard to run when the supplier is two weeks away by sea.
Common phrases
just-in-time delivery · just-in-time production · move to just-in-time · JIT supplier
A signal, usually a card or an empty bin, that tells the previous step or the supplier to make or deliver more parts. The Japanese word means 'signboard'.
Where you use it
Used for the card itself (a kanban) and for the whole system. Planners calculate the number of kanbans in a loop, and operators send a kanban back when a bin is empty. Electronic kanban (e-kanban) works the same way through software. Kanban boards in software teams come from the same idea.
Examples
When the bin is empty, put the kanban in the post box and the material handler will refill it.
We reduced the number of kanban cards in the loop from 12 to 8 to cut inventory.
Common phrases
kanban card · kanban system · e-kanban · kanban loop
A simple device or design feature that prevents a mistake or makes it obvious at once, such as a part that can only fit one way. Japanese for 'mistake-proofing'.
Where you use it
Developed by Shigeo Shingo for the Toyota Production System. Engineers design, add or install a poka-yoke, and corrective action plans often include one. In English people also say mistake-proofing or error-proofing; 'fool-proofing' is older and less polite.
Examples
We added a poka-yoke pin to the fixture so the bracket can't be loaded upside down.
A sensor checks that all four screws are in place; it's our poka-yoke for missing screws.
A way of controlling production in which a step makes or delivers parts only when the next step uses them up, instead of working to a forecast.
Where you use it
The opposite of a push system, where work is pushed through the plant according to a schedule. Pull is usually set up with kanban or supermarkets and keeps work in progress low. Lean teams talk about moving from push to pull.
Examples
With the new pull system, the machining cell only starts a job when the assembly supermarket needs it.
Moving to a pull system cut work in progress between the two buildings by 60%.
Common phrases
set up a pull system · push versus pull · move to a pull system · kanban pull
Short for single-minute exchange of die: a method for cutting changeover time to under ten minutes by doing as much setup work as possible while the machine is still running.
Where you use it
Developed by Shigeo Shingo. The key idea is to separate internal setup (possible only when the machine is stopped) from external setup (possible while it runs), then turn internal work into external work. Teams usually run a SMED workshop on one machine at a time.
Examples
After the SMED workshop, mold changes on the injection machine went from 75 to 18 minutes.
Using SMED, we moved die preheating outside the changeover.
Usage note
'Single-minute' does not mean one minute; it means a time that can be written with a single digit, so under ten minutes.
A Japanese word meaning 'the real place': where the actual work is done, such as the shop floor, the warehouse or the lab.
Where you use it
Lean thinking says managers should go to the gemba to see problems with their own eyes instead of relying only on reports. A gemba walk is a regular visit to the shop floor to observe, ask questions and support teams. Sometimes spelled 'genba'.
Examples
The plant manager does a gemba walk every morning at nine.
Don't try to solve it from the office; let's go to the gemba and look at the machine.
Common phrases
gemba walk · go to the gemba · gemba visit · on the gemba
Describing an activity that changes a product in a way the customer is willing to pay for, such as machining, assembling or painting it.
Where you use it
Used in lean analysis to sort activities into value-added, non-value-added (pure waste) and necessary non-value-added (such as legally required checks). Teams calculate value-added time as a share of total lead time, which is often only a few percent.
Examples
Only 6 minutes of the 4-hour process are value-added; the rest is moving and waiting.
Inspection is not a value-added step, but the customer requires it for now.
Usage note
In finance, 'value added' also means the extra value a company creates, as in value-added tax (VAT).
Common phrases
value-added time · value-added activity · non-value-added · value-added ratio
A data-driven method for improving processes by reducing variation and defects, aiming for no more than 3.4 defects per million opportunities.
Where you use it
Developed at Motorola in the 1980s and made famous by General Electric. Projects follow the DMAIC steps, and people are trained to belt levels such as Yellow, Green and Black Belt. Many companies combine it with lean as 'Lean Six Sigma'.
Examples
She is a certified Six Sigma Black Belt and leads our biggest quality projects.
This Six Sigma project cut paint defects by 70% in six months.
Usage note
Write it with capital letters as a name: Six Sigma. The Greek letter sigma (σ) is the statistical symbol for standard deviation.
Common phrases
Six Sigma project · Lean Six Sigma · Six Sigma Green Belt · Six Sigma methodology
The five-phase roadmap of a Six Sigma project: Define, Measure, Analyze, Improve and Control.
Where you use it
Projects move through the DMAIC phases, often with a gate review at the end of each one. People say 'we are in the Measure phase'. It is usually pronounced 'duh-MAY-ik'. DMADV is a related roadmap for designing new processes.
Examples
We are following DMAIC, and the Measure phase should be finished by the end of May.
In the Control phase of DMAIC, we handed the new control plan over to production.
The natural differences between the results of the same process, for example small changes in the diameter of parts made on the same machine.
Where you use it
The main enemy in Six Sigma and SPC. Engineers measure, reduce and control variation, and separate common-cause variation (always present, part of the system) from special-cause variation (from a specific event, like a broken tool).
Examples
There is too much variation between the two shifts; the night shift's parts are always thicker.
Reducing variation in the oven temperature solved most of the color problems.
Common phrases
reduce variation · process variation · common-cause variation · special-cause variation · source of variation
How well a stable process can produce parts within the specification limits, usually expressed with indices such as Cp and Cpk.
Where you use it
Customers often ask for capability studies before approving a new part. Cp compares the tolerance width with the process spread (6σ); Cpk also checks how well the process is centered. Many automotive customers require a Cpk of at least 1.33, and higher for new processes.
Examples
Process capability for the bore diameter is too low: Cpk is only 0.9.
We need a process capability study on 125 parts before the customer approves the new tool.
Usage note
Do not confuse capability with capacity: capability is about quality and tolerances, capacity is about volume.
Common phrases
process capability study · process capability index · Cpk value · improve process capability
A number that shows how widely values are spread around their average; a small standard deviation means the results are close together. Its symbol is σ (sigma).
Where you use it
Used everywhere in quality and Six Sigma work, from control limits to capability indices. People calculate the standard deviation of a sample and say values are 'within two sigma' or 'three standard deviations from the mean'.
Examples
The mean fill weight is 500.4 g with a standard deviation of 0.8 g.
Control limits are set at three standard deviations above and below the mean.
Common phrases
calculate the standard deviation · sample standard deviation · three standard deviations · high standard deviation
Short for defects per million opportunities: the number of defects divided by the total number of chances for a defect, multiplied by one million.
Where you use it
The standard way to express a sigma level in Six Sigma; 3.4 DPMO corresponds to Six Sigma quality. It allows comparison between simple and complex products. It differs from ppm, which counts defective parts rather than defect opportunities.
Examples
We found 18 defects in 500 boards with 40 opportunities each, which is 900 DPMO.
Our goal is to bring the soldering process below 1,000 DPMO this year.
A fault in a product or part that means it does not meet its specification, such as a scratch, a crack, a wrong dimension or a missing component.
Where you use it
Used constantly in quality meetings and reports. Inspectors find, detect and record defects; teams aim for zero defects and measure defect rates, often in ppm (parts per million). A part with a defect is called defective.
Examples
The customer found a surface defect on 12 parts from batch 2207.
Our defect rate fell to 150 ppm after we added the vision camera.
Usage note
As a noun it is stressed on the first syllable (DEE-fect). The verb 'to defect', stressed on the second syllable, means to leave your side or country.
Common phrases
defect rate · zero defects · surface defect · detect a defect · defective part
Material or parts that are defective or left over and cannot be used or repaired, so they are thrown away or recycled. As a verb, to throw such parts away.
Where you use it
Used as a noun (scrap rate, scrap cost) and as a verb (scrap a batch). Quality and finance teams track scrap closely because it is pure loss. As a noun it is usually uncountable: 'a lot of scrap'.
Examples
We had to scrap 400 housings because the wrong alloy was used.
Scrap on the injection molding line is now below 2%.
Common phrases
scrap rate · scrap a batch · scrap cost · reduce scrap · scrap bin
Extra work done to correct a defective product so that it meets the specification, instead of scrapping it. It is also a verb meaning to do this work.
Where you use it
Used in quality and cost discussions. Parts are sent to rework, put in the rework area or reworked. Rework saves material but costs labor and time, and lean thinking counts it as a form of waste.
Examples
About 5% of the welded frames need rework before painting.
Can these parts be reworked, or do we have to scrap them?
Usage note
As a noun it is stressed on the first syllable (REE-work); as a verb, usually on the second (re-WORK).
Common phrases
rework area · send to rework · rework cost · rework rate
The work of checking products and processes against set standards to find defects and keep quality at the required level. Often shortened to QC.
Where you use it
Refers both to the activity and to the department (QC). Quality control focuses on checking and finding problems; quality assurance (QA) focuses on building systems that prevent them. People say a batch passed or failed QC.
Examples
The batch is on hold until quality control releases it.
Our quality control team checks five samples from every pallet.
Usage note
QC (control) and QA (assurance) are different: QC finds defects, QA tries to prevent them. Many Turkish companies call both 'kalite kontrol'.
Common phrases
quality control check · pass quality control · quality control department · incoming quality control
Looking at, measuring or testing a product to decide whether it meets its requirements, for example checking dimensions with a gauge.
Where you use it
Used for incoming inspection (material from suppliers), in-process inspection and final inspection. Inspectors carry out or perform inspections, and parts pass or fail them. 100% inspection means every single part is checked.
Examples
All castings go through 100% visual inspection before machining.
Final inspection found two units with loose screws.
Usage note
For checking a product, English usually says 'inspection' or 'check', not 'control'. 'Control' means keeping a process within limits.
Common phrases
final inspection · incoming inspection · visual inspection · carry out an inspection · pass inspection
A method of monitoring a process with statistics, usually control charts, to spot unusual variation early and keep the process stable. Shortened to SPC.
Where you use it
Common in automotive and other high-volume industries, where customers often require it on key characteristics. Operators take samples, plot them on SPC charts and react when a point is out of control. SPC software can collect data directly from gauges.
Examples
The customer requires statistical process control on all critical dimensions.
Thanks to statistical process control, we saw the tool wear trend before any bad parts were made.
Common phrases
SPC chart · implement statistical process control · SPC data · SPC software
A graph that shows measurements of a process over time, with a center line and upper and lower control limits, so you can see whether the process is stable.
Where you use it
Developed by Walter Shewhart in the 1920s. Common types are X-bar and R charts for measurements and p-charts for defect rates. Points outside the limits, or unusual patterns such as a long run of points on one side of the center line, signal a special cause to investigate.
Examples
The control chart shows the diameter drifting upward since the tool change.
Two points on the control chart are above the upper limit, so stop the machine and call quality.
Usage note
Control limits come from the process data; specification limits come from the customer or the drawing. Parts can be within specification while the process is out of control.
Common phrases
X-bar and R chart · upper control limit · plot on a control chart · out of control
An action taken to remove the cause of a problem or nonconformance so that it does not happen again, not just to fix the affected parts.
Where you use it
A key term in ISO 9001 and customer quality systems. Teams take, implement and verify corrective actions, often in an 8D or CAPA (corrective and preventive action) report. A containment action, such as sorting stock, is the quick first step; corrective action follows the root cause analysis.
Examples
As a corrective action, we added a torque check to the control plan and retrained the operators.
The customer will close the complaint only after we prove the corrective action is effective.
Common phrases
take corrective action · corrective action plan · verify corrective action · corrective and preventive action
A failure to meet a specified requirement in a product, a process or a management system, for example a part outside tolerance or a skipped procedure step.
Where you use it
Quality teams raise, record and close nonconformances, often with an NCR (nonconformance report). Nonconforming products are tagged and moved to a quarantine area. Auditors classify their findings as major or minor nonconformances.
Examples
The auditor raised a minor nonconformance because two gauges were past their calibration date.
Please open a nonconformance report for the wrong labels and put the pallets in quarantine.
Usage note
ISO standards use 'nonconformity'; 'nonconformance' is common in industry. Both are understood and used for the same idea.
Common phrases
nonconformance report · raise a nonconformance · major nonconformance · close a nonconformance
The percentage of units that come out of a process right the first time, with no rework, repair or scrap. Shortened to FPY.
Where you use it
A quality KPI shown next to scrap and defect rates. If 1,000 units start and 920 pass without any rework, FPY is 92%. For a line with several steps, rolled throughput yield (RTY) multiplies the FPY of each step.
Examples
First pass yield at the end-of-line test went up from 88% to 96% after the software fix.
Our first pass yield looks good on paper, but many units are quietly repaired before final inspection.
Common phrases
improve first pass yield · FPY target · rolled throughput yield · right first time
Short for failure mode and effects analysis: a structured team method for listing how a product or process could fail, what the effects would be, and how to prevent the most serious risks.
Where you use it
Used for designs (DFMEA) and processes (PFMEA), especially in automotive. Each failure mode is rated for severity, occurrence and detection. Traditionally these were multiplied into an RPN; the 2019 AIAG-VDA handbook uses Action Priority instead. Teams create, review and update the FMEA.
Examples
The PFMEA for the new line lists 120 failure modes, and 14 of them need action.
After the field failure, we had to update the FMEA and add a new detection control.
Common phrases
process FMEA · design FMEA · update the FMEA · FMEA team · risk priority number
A planned, independent check of whether a process, product or management system follows the required standards, procedures and rules.
Where you use it
Plants face internal audits, customer audits and certification audits, for example for ISO 9001, IATF 16949 or ISO 45001. Auditors conduct an audit and raise findings, and the company prepares for and passes it. Also used as a verb: to audit a supplier.
Examples
The customer audit is next Tuesday, so the whole plant needs to be ready.
We passed the ISO 9001 surveillance audit with two minor findings.
Common phrases
internal audit · customer audit · pass an audit · audit finding · conduct an audit
An ongoing effort to make products, processes and services better through many small, regular changes rather than one big change. Often shortened to CI.
Where you use it
Used as a goal, a culture and a job title (continuous improvement engineer, CI manager). Companies build a culture of continuous improvement and run CI projects. ISO 9001 also asks organizations to show improvement over time.
Examples
Our continuous improvement team collected 340 ideas from operators last year.
Continuous improvement is not a project with an end date; it's how we work every day.
Usage note
ISO standards say 'continual improvement' (repeated over time); in daily speech 'continuous improvement' is more common.
A Japanese word for 'change for the better', used for small, steady improvements made by everyone, and for a short, focused improvement event.
Where you use it
Used as a noun in two ways: the general idea of daily improvement, and a kaizen event or blitz, a three-to-five-day workshop on one area. People run, hold or lead a kaizen and submit kaizen ideas.
Examples
We ran a three-day kaizen on the packing area and cut walking distance by half.
Each team is expected to submit at least two kaizen ideas a month.
Common phrases
kaizen event · run a kaizen · kaizen blitz · kaizen idea · kaizen team
A written, step-by-step description of how a task must be done, so that everyone does it the same, safe and correct way. Usually shortened to SOP.
Where you use it
People write, follow, update and train on SOPs, and auditors check that workers use the current version. On the shop floor a simpler one-page version is often called a work instruction. The abbreviation is said letter by letter: S-O-P.
Examples
Please follow the standard operating procedure for cleaning the mixer; it changed last month.
Every new operator signs the standard operating procedure (SOP) after training.
Common phrases
follow the SOP · write a standard operating procedure · update the SOP · SOP training
A structured way of finding the deepest reason for a problem, so that it can be fixed for good instead of only treating the symptoms. Often shortened to RCA.
Where you use it
Customers often ask for it after a complaint. Teams carry out or do a root cause analysis using tools like 5 Whys, fishbone diagrams and data analysis. Problem-solving reports such as 8D have a separate root cause section.
Examples
The customer wants a root cause analysis and a corrective action plan within ten days.
Our root cause analysis showed that the sensor had been moved during cleaning.
Common phrases
carry out a root cause analysis · root cause analysis report · find the root cause · RCA tools
A bar chart that sorts problems or causes from the most to the least frequent, with a line showing the cumulative percentage, so a team can focus on the few that matter most.
Where you use it
One of the seven basic quality tools. It is based on the Pareto principle, or 80/20 rule: roughly 80% of problems come from 20% of causes. Teams make a Pareto chart of defects or downtime reasons and attack the top bars first.
Examples
The Pareto chart shows that three defect types make up 75% of all complaints.
Let's make a Pareto chart of last month's downtime reasons before the meeting.
Usage note
Named after the Italian economist Vilfredo Pareto; English speakers say 'puh-RAY-toh'.
Common phrases
Pareto chart of defects · Pareto analysis · 80/20 rule · top three on the Pareto
A cause-and-effect diagram shaped like a fish skeleton: the problem is the head, and the bones list possible causes in groups such as people, machine, method, material, measurement and environment.
Where you use it
Used in brainstorming sessions during root cause analysis. Teams draw or fill in a fishbone diagram, then test the most likely causes with data. It is also called an Ishikawa diagram after Kaoru Ishikawa, and the main groups are often called the 6Ms.
Examples
We listed 23 possible causes on the fishbone diagram, but only three were confirmed by data.
Let's start with a fishbone diagram and look at the machine and method branches first.
Usage note
In the traditional 6Ms the first M is 'man'; many companies now say 'manpower' or 'people' instead.
A simple root cause technique in which you keep asking 'why?' about a problem, about five times, until you reach a cause you can actually fix.
Where you use it
Developed within Toyota and used in 8D reports and daily problem solving. Teams do a 5 Whys, ideally on the shop floor with the people involved. Five is a guide, not a rule, and the chain should end at a process cause, not at blaming a person.
Examples
We did a 5 Whys on the leak and found that the torque tool had not been calibrated since March.
Don't stop the 5 Whys at 'operator error'; ask why the error was possible.
Common phrases
do a 5 Whys · 5 Whys analysis · 5 Whys template · ask why five times
A four-step improvement loop: Plan a change, Do it on a small scale, Check the results, then Act by making it standard or trying again.
Where you use it
Also called the Deming cycle or Shewhart cycle. It is the logic behind ISO management system standards and many improvement methods. People talk about going around the PDCA cycle and closing the loop. A version with Study instead of Check (PDSA) is also used.
Examples
We're in the Check step of the PDCA cycle: the new settings have run for two weeks.
Every improvement on the board follows the PDCA cycle, and the color shows which step it is in.
Common phrases
PDCA approach · go around the PDCA cycle · Plan-Do-Check-Act · close the loop
To make a process simpler and more efficient, usually by removing unnecessary steps, approvals or handoffs.
Where you use it
A common verb in reports, presentations and job ads. People streamline a process, a workflow or an approval chain. The adjective 'streamlined' describes a simple, efficient process: a streamlined order process.
Examples
We streamlined the engineering change process from 14 signatures to 5.
The goal of the project is to streamline material handling between the warehouse and the lines.
Common phrases
streamline a process · streamline operations · streamlined workflow · streamline approvals
A mathematical method for finding the best result, such as the lowest cost or highest profit, when the goal and all the limits can be written as linear equations.
Where you use it
A core operations research tool, used for product mix, blending, transport and scheduling problems. Engineers formulate an LP model with decision variables, an objective function and constraints, then solve it with the simplex method (George Dantzig, 1947) or a solver such as Excel Solver.
Examples
We used linear programming to find the product mix that gives the highest profit with the current machine hours.
The linear programming model has 40 variables and 25 constraints.
Usage note
'Programming' here means planning, not writing computer code; the name comes from military planning work in the 1940s.
Common phrases
linear programming model · formulate a linear programming problem · LP solver · simplex method
Finding the best possible solution among many options within given limits, for example the cheapest route, the shortest schedule or the best use of machines.
Where you use it
Used both for mathematical methods (linear and integer programming, heuristics) and, more loosely, for any improvement. People run an optimization, use optimization software and talk about cost or schedule optimization. Analysts warn against improving one area at the expense of the whole system.
Examples
Route optimization cut our trucks' fuel use by about 9%.
With schedule optimization, the planner gets a first plan in minutes instead of a full day.
Usage note
British English often writes 'optimisation'. 'Optimal' is the usual adjective: the optimal solution.
Common phrases
cost optimization · run an optimization · optimization model · optimization software
A computer model that imitates how a real system, such as a factory, warehouse or queue, behaves over time, so you can test changes before making them.
Where you use it
Industrial engineers mostly use discrete-event simulation in tools such as Arena, FlexSim or Simio. They build a simulation model, run scenarios and compare results like throughput and waiting time. It is useful when variation makes simple calculations unreliable.
Examples
The simulation shows that a second loading dock would cut truck waiting time by 40%.
Before we spend money on the new layout, let's test it in a simulation.
Common phrases
simulation model · discrete-event simulation · run a simulation · simulation results
The mathematical study of waiting lines: how arrivals, service times and the number of servers affect queue length and waiting time.
Where you use it
Used to size call centers, checkouts, loading docks and machine groups. Key ideas include arrival rate, service rate and utilization. Little's Law (L = λW) links the average number of items in a system, the arrival rate and the average time spent in the system.
Examples
Queueing theory explains why waiting times explode when the forklift fleet is more than 90% busy.
We used a simple queueing theory model to decide how many repair technicians we need per shift.
Usage note
Both 'queueing' and 'queuing' are correct; operations research texts usually write 'queueing'. In US English a queue is often called a 'line'.
Common phrases
queueing model · waiting line · arrival rate · service rate · Little's Law
In an optimization model, the formula that measures what you want to minimize or maximize, such as total cost, profit or delivery time.
Where you use it
Every linear programming or optimization model has an objective function and a set of constraints. People write, define, minimize or maximize the objective function and report its optimal value. When there are several goals, they can be weighted and combined into one function.
Examples
The objective function minimizes total transport cost from three plants to twelve warehouses.
If we add overtime cost to the objective function, the model chooses a different schedule.
Common phrases
minimize the objective function · maximize the objective function · objective function value · define the objective function
A limit that a solution must respect, such as available machine hours, budget or storage space. In the Theory of Constraints, the resource that limits the whole system.
Where you use it
Used in optimization models (capacity constraints, demand constraints) and in everyday planning talk ('our main constraint is space'). Eliyahu Goldratt's Theory of Constraints (TOC), known from his book 'The Goal', focuses improvement on the system's constraint.
Examples
The model has a constraint that no machine can run more than 120 hours a week.
Floor space, not labor, is now the main constraint in the warehouse.
Common phrases
capacity constraint · main constraint · Theory of Constraints · subject to constraints · relax a constraint
All the materials and products a company holds: raw materials, parts, work in progress and finished goods waiting to be sold.
Where you use it
Used in planning, finance and lean. Companies hold, carry, count, reduce and manage inventory, and finance looks at inventory value and turns. In lean, excess inventory is a waste because it hides problems and ties up cash.
Examples
We are holding six weeks of inventory for this part, which is far too much.
The year-end inventory count starts on Friday after the last shift.
Usage note
US English says 'inventory'; British English often says 'stock' for the same thing. Inventory is usually uncountable.
A basic material, such as steel coil, plastic granules or cotton, that a factory turns into parts or products.
Where you use it
Usually used in the plural (raw materials). Purchasing buys raw materials, quality checks them at incoming inspection and planning watches raw material stock. Raw material prices are a major part of product cost.
Examples
Raw material costs went up 12% this quarter because of steel prices.
We can't start the order until the raw material passes incoming inspection.
Common phrases
raw material cost · raw material stock · raw material supplier · shortage of raw materials
Products that have been started but are not finished yet, such as parts waiting between machines. Often shortened to WIP.
Where you use it
The abbreviation is said as a word, 'wip'. Lean teams limit and reduce WIP because piles of half-finished parts hide problems and slow the flow. Finance also reports WIP as part of inventory value. In US English 'work in process' is also common.
Examples
There is too much work in progress between welding and painting; the racks are full.
Cutting work in progress by half also halved our production lead time.
Common phrases
reduce work in progress · WIP limit · WIP inventory · level of work in progress
Products that are completely made, checked and ready to be shipped or sold to customers.
Where you use it
Always plural. One of the three main types of inventory, next to raw materials and work in progress. Planners watch finished goods stock, and finished goods are kept in the FG warehouse until shipping.
Examples
We have three days of finished goods in stock, enough to cover the holiday.
Finished goods are moved to the shipping area twice a shift.
Extra stock kept on top of normal needs to protect against unexpected demand or supplier delays.
Where you use it
Planners set, calculate and review safety stock, often based on the variation in demand and lead time. Too much ties up cash and space; too little risks stopping the line. It is also called buffer stock.
Examples
We keep two weeks of safety stock for the imported chips.
Safety stock for this item was set years ago and nobody has reviewed it since.
Common phrases
safety stock level · hold safety stock · calculate safety stock · dip into safety stock
The stock level at which a new order must be placed so that the material arrives before you run out. Often shortened to ROP.
Where you use it
Usually calculated as the average demand during the lead time plus safety stock. ERP systems can create a purchase requisition when stock falls below the reorder point. Planners set, review and adjust reorder points when demand or lead times change.
Examples
We use 200 bolts a day, the lead time is 5 days and safety stock is 400, so the reorder point is 1,400.
Stock has fallen below the reorder point, so purchasing has already sent the order.
Common phrases
set the reorder point · fall below the reorder point · reorder level · reorder quantity
The order size that gives the lowest total cost by balancing the cost of placing orders against the cost of holding stock. Shortened to EOQ.
Where you use it
A classic model first published by Ford W. Harris in 1913: EOQ = √(2DS/H), where D is annual demand, S the cost per order and H the yearly holding cost per unit. In practice it is a starting point, adjusted for minimum order quantities and price discounts.
Examples
The economic order quantity for this resin is about 2,000 kg, but the supplier's minimum is 5,000 kg.
If holding costs go up, the economic order quantity goes down.
Common phrases
calculate the economic order quantity · EOQ model · EOQ formula · holding cost · ordering cost
Sorting stock items into three groups by value: A items are few but make up most of the value, C items are many but low in value, and B items are in between.
Where you use it
Based on the Pareto principle: often around 20% of items make up 80% of annual consumption value. Planners use ABC analysis to decide how tightly to control each item, for example counting A items more often and reviewing their safety stock carefully.
Examples
According to our ABC analysis, 140 A items account for 78% of inventory value.
Let's update the ABC analysis before we change the stock counting plan.
Common phrases
A items · ABC class · ABC classification · carry out an ABC analysis
Short for first in, first out: using or shipping the oldest stock first, so that materials do not age, expire or get forgotten at the back of the shelf.
Where you use it
Used in warehouses, on the shop floor and in accounting. Racks and lanes are designed so FIFO happens naturally, for example by loading from the back and picking from the front. In food and pharma, FEFO (first expired, first out) is often used instead.
Examples
Please follow FIFO: take the pallets with the oldest labels first.
The new flow racks make FIFO automatic for small parts.
The time it takes to complete one unit or one full round of a task at a machine or workstation, from start to finish.
Where you use it
Measured with a stopwatch or machine data and given in seconds or minutes. Engineers measure, reduce and cut cycle time. Some companies also use it for the total time an order spends in the plant, so check which meaning is intended.
Examples
The robot's cycle time is 42 seconds, but takt time is only 38, so we need a second cell.
We cut the cycle time by 15% by moving the parts bin closer to the operator.
Usage note
Cycle time is how long a step actually takes; takt time is how fast you need to produce to meet demand; lead time is the customer's total wait.
Common phrases
reduce cycle time · machine cycle time · average cycle time · measure cycle time
The systematic study of how work is done, using method study and work measurement, to find better methods and set fair time standards.
Where you use it
A classic industrial engineering term, used in courses and in plants with a work study or IE department. It has two parts: method study (how the job should be done) and work measurement (how long it should take). Its roots go back to Taylor and the Gilbreths.
Examples
A work study of the loading area showed that drivers spent 30% of their time waiting.
Before we buy another machine, let's do a proper work study of the current method.
Common phrases
carry out a work study · work study engineer · method study · work measurement
A work measurement method in which an analyst times a trained worker doing a task many times, usually with a stopwatch or video, to set a standard time.
Where you use it
Engineers carry out a time study, break the job into elements, record observed times and then apply a performance rating and allowances. Workers should be told about the study in advance. The method is linked to Frederick Taylor.
Examples
We did a time study on the new harness assembly: 20 cycles of eight elements each.
The time study showed that element 5, fitting the clip, takes the longest.
Common phrases
carry out a time study · stopwatch time study · time study sheet · time study results
The time a trained worker working at a normal pace needs to do a task, including allowances for rest, personal needs and small delays.
Where you use it
Calculated in two steps: observed time × performance rating = normal time, then normal time × (1 + allowance). Standard times are used for costing, capacity planning, line balancing and incentive pay, so they are often discussed with unions.
Examples
The standard time for this operation is 3.2 minutes, including a 12% allowance.
We need to update the standard times now that the new jig is in use.
Common phrases
set a standard time · update standard times · standard time per unit · standard minute
The detailed study of the body movements a worker uses to do a task, in order to remove unnecessary movements and find an easier, faster method.
Where you use it
Pioneered by Frank and Lillian Gilbreth, who broke work into basic motions called therbligs (their surname spelled almost backwards). Today it is often done with video, and it is closely linked to ergonomics and the principles of motion economy.
Examples
The motion study showed that operators turned around 30 times an hour to reach the parts bins.
We filmed the station for a motion study and found that both hands were rarely working at the same time.
Common phrases
time and motion study · carry out a motion study · principles of motion economy · therblig
Extra time added to the normal time of a task to cover rest, personal needs and unavoidable delays, usually given as a percentage.
Where you use it
Used in time study and standard time calculations. The common types are personal, fatigue (rest) and delay allowances, often written PF&D. Heavy, hot or tiring work gets higher allowances. People add, apply or set an allowance.
Examples
We applied a 15% allowance for fatigue and personal needs on the foundry jobs.
The standard time looks too tight because the allowance for machine delays was left out.
Usage note
Do not translate 'tolerans' in this sense as 'tolerance'; in English, tolerance means the allowed variation in a dimension. In US English, allowance is also the pocket money parents give children.
Common phrases
fatigue allowance · personal allowance · PF&D allowance · apply an allowance
In time study, the analyst's judgment of how fast a worker is working compared with a normal pace, used to turn observed time into normal time.
Where you use it
Given as a percentage: 100% is normal pace, and 110% means faster than normal. Normal time = observed time × rating. Rating takes training and practice, and workers and unions often question it because it is partly subjective.
Examples
The observed time was 50 seconds and I gave a performance rating of 90%, so the normal time is 45 seconds.
Two engineers rated the same video to check that their performance ratings agree.
Usage note
In HR, 'performance rating' means an employee's yearly evaluation score, which is a different meaning from the one in time study.
Common phrases
performance rating factor · apply a performance rating · normal time · rating scale
A work measurement method that uses many random, short observations to estimate what share of time people or machines spend on different activities.
Where you use it
Useful for long, varied or group work where a stopwatch study is not practical, such as maintenance or office tasks. The analyst records what is happening at random moments, and more observations give a more accurate result. Also called activity sampling.
Examples
Work sampling over two weeks showed that the forklift drivers were idle 35% of the time.
We need about 600 observations for the work sampling to be accurate within 4%.
Common phrases
work sampling study · random observations · activity sampling · sampling accuracy
The study and design of work so that it fits the human body and mind, reducing strain, injury and errors while improving comfort and performance.
Where you use it
Used in workstation design, safety and health. Engineers improve the ergonomics of a workstation, carry out ergonomic assessments and look for poor postures, heavy lifting and repeated movements. The adjective is 'ergonomic': an ergonomic chair.
Examples
Raising the table by 15 cm made a big difference to the ergonomics of the packing station.
We do an ergonomic assessment of every new workstation before it goes live.
Usage note
As the name of a field, ergonomics takes a singular verb: 'Ergonomics is part of every new line design.'
The measurement of the human body, such as height, reach and hand size, used to design workstations, tools and equipment that fit the people who use them.
Where you use it
Designers use anthropometric data tables and usually design for the 5th to 95th percentile of the user population, so that most people fit. Adjustable heights and defined reach zones are typical results. The adjective is 'anthropometric'.
Examples
Using anthropometric data, we set the shelf height so that 95% of operators can reach it without stretching.
Anthropometry tells us the work table must be adjustable between 85 and 105 cm.
Common phrases
anthropometric data · 5th to 95th percentile · reach zone · body dimensions
An injury or painful condition of the muscles, tendons, joints, nerves or back, often caused by repeated movements, heavy lifting or awkward postures at work. Shortened to MSD.
Where you use it
Usually used in the plural (MSDs). Examples include low back pain, carpal tunnel syndrome and tendinitis. Ergonomists assess the risk of musculoskeletal disorders with tools such as RULA, REBA or the NIOSH lifting equation, and redesign jobs to prevent them.
Examples
Most of our lost-time injuries last year were musculoskeletal disorders from lifting boxes.
Job rotation every two hours has reduced musculoskeletal disorders on the packing line.
Lifting, carrying, pushing, pulling or holding loads using the body rather than machines; one of the most common causes of back injuries at work.
Where you use it
Common in UK and EU safety language; Americans often say 'manual material handling'. Companies carry out manual handling risk assessments and training, and reduce manual handling with lifting aids, trolleys and lighter loads.
Examples
The new vacuum lifter removed almost all manual handling of the 25 kg bags.
All warehouse staff must complete manual handling training in their first week.
The study of how people's abilities, limits and behavior affect their work with machines, systems and procedures, used to design work that reduces errors.
Where you use it
Often used together with ergonomics, but with more focus on the mind: attention, fatigue, workload, displays and decision making. Investigations look at human factors instead of simply blaming 'human error'. Common in aviation, healthcare and control rooms.
Examples
The investigation found human factors behind the error: a confusing screen and a 12-hour shift.
We asked a human factors specialist to review the new control panel layout.
Common phrases
human factors engineering · human factors specialist · human error · cognitive workload
Short for personal protective equipment: safety glasses, gloves, helmets, ear protection, safety shoes and other gear that protects workers from hazards.
Where you use it
Seen on signs and in safety briefings everywhere in a plant. Workers wear PPE, and supervisors check that the required PPE is worn in each area. PPE is the last line of defense: first remove or control the hazard itself.
Examples
PPE is mandatory beyond this point: safety glasses, hearing protection and steel-toe shoes.
Visitors must collect their PPE at the security gate.
Usage note
PPE is normally uncountable: say 'PPE' or 'items of PPE' rather than 'PPEs'.
Common phrases
wear PPE · required PPE · PPE check · PPE is mandatory
Anything that could cause harm, injury or ill health, such as moving machine parts, chemicals, noise, electricity or a wet floor.
Where you use it
Used in risk assessments, safety walks and on signs. People identify, report, control and remove hazards. In safety language a hazard is the possible source of harm, while risk is how likely and how serious that harm is.
Examples
Oil on the floor near press 3 is a slip hazard; please clean it up now.
During the safety walk we found four new hazards in the warehouse.
Usage note
Hazard and risk are not the same: a sharp blade is a hazard; the chance that someone gets cut, and how badly, is the risk.
Common phrases
identify hazards · slip hazard · fire hazard · report a hazard · hazard control
A careful review of a task or area to find the hazards, judge how likely and how serious harm would be, and decide what controls are needed.
Where you use it
Required by law in many countries, including Turkey, and reviewed when processes change. Safety teams carry out, update and sign off risk assessments, often scoring risk as likelihood × severity. A new machine or task should not start without one.
Examples
We can't install the new robot until the risk assessment is signed off.
The risk assessment rated forklift traffic near the exit as high risk.
Common phrases
carry out a risk assessment · update the risk assessment · risk assessment form · sign off a risk assessment
An unplanned event that could have caused injury or damage but did not, such as a box falling from a rack where someone had just been standing.
Where you use it
Workers are encouraged to report near misses, because they share the same causes as real accidents. Safety teams log, investigate and track them; a high number of reports usually means a healthy safety culture, not a dangerous plant.
Examples
I'd like to report a near miss: a forklift came round the corner too fast and almost hit a visitor.
We received 58 near miss reports this month, more than ever before.
Usage note
It may sound odd, but 'near miss' means the accident nearly happened. Some people say 'near hit' or 'close call' instead.
Common phrases
report a near miss · near miss report · near miss investigation · near miss board
A safety procedure in which machines are shut off and their energy sources are locked and tagged before maintenance, so they cannot be started by accident. Shortened to LOTO.
Where you use it
Every person working on the machine puts their own lock on the isolation point and keeps the key. Energy means not only electricity but also hydraulic, pneumatic, stored and gravitational energy. Skipping lockout/tagout is a common cause of serious injuries.
Examples
Nobody puts their hands inside the press without lockout/tagout, even for a quick fix.
Each maintenance technician carries a lockout/tagout kit with personal locks and tags.
Usage note
Pressing an emergency stop is not lockout: it does not isolate the energy, so it is not safe for maintenance work.
Common phrases
lockout/tagout procedure · apply lockout/tagout · LOTO lock · isolation point · zero energy state
A document from the supplier of a chemical that describes its hazards, safe handling and storage, first aid, firefighting measures and the PPE needed. Shortened to SDS.
Where you use it
Under the UN's GHS system, an SDS has 16 standard sections. Every chemical on site must have an up-to-date SDS that workers can easily reach. The older name MSDS (material safety data sheet) is still heard.
Examples
Check section 8 of the safety data sheet to see which gloves you need with this solvent.
We can't accept a new chemical into the plant without its safety data sheet.
Common phrases
up-to-date safety data sheet · SDS section · request the SDS · material safety data sheet
Physical barriers and safety devices, such as fixed covers, interlocked doors and light curtains, that keep people away from the dangerous moving parts of machines.
Where you use it
A frequent topic in safety audits and new machine approvals. Guards must not be removed or bypassed, and an interlock stops the machine when a door opens. People install, check and repair guarding, and report missing or damaged guards.
Examples
The audit found that the machine guarding on the old lathe had been removed and never replaced.
Never bypass machine guarding to clear a jam; stop the machine and lock it out.
A large red button or switch, usually on a yellow background, that stops a machine as quickly as possible in a dangerous situation. Shortened to E-stop.
Where you use it
Every operator should know where the emergency stops are. People press or hit the E-stop, and it must be reset before the machine restarts. E-stops are tested regularly, and pull cords along conveyors do the same job.
Examples
When she saw the operator's glove caught in the rollers, she hit the emergency stop at once.
Test every emergency stop on the line at the start of each week.
Usage note
An emergency stop is for emergencies, not for normal stopping; using it as an on/off switch can damage equipment and hide real faults.
Common phrases
press the emergency stop · E-stop button · reset the E-stop · emergency stop test · pull cord
Ten questions from this glossary. Pick the right meaning for each term and see your score.
How to learn industrial engineering & manufacturing vocabulary
Read real texts from the field: customer quality manuals, audit and 8D reports, ERP screens, lean training material and the safety signs and work instructions on the shop floor all use this vocabulary in its natural context.
Learn each term with the verbs that go with it: not just 'downtime' but 'reduce downtime', 'log downtime' and 'unplanned downtime'; not just 'takt time' but 'meet takt time'.
Learn abbreviations with their full form and the way they are said: OEE and SOP are said letter by letter, while WIP and SMED are said as words. Be ready to explain them to a visitor who does not know them.
Practice turning numbers into short sentences, the way you would in a shift meeting or a report: 'OEE dropped from 78 to 71 percent because of two long breakdowns on Line 3.' Remember that English uses a decimal point, not a comma.
Keep a list of words that look familiar but mean something specific in this field, such as waste (israf, not just atık), control (keeping a process within limits, not checking a product) and allowance (pay, not tolerance).
Frequently asked questions
How can I learn English for industrial engineering?
Read real texts from the field and notice how the words are used: customer quality manuals, audit and 8D reports, ERP screens, lean training material and safety instructions. Learn each term together with its usual partners (reduce downtime, meet takt time, raise a nonconformance) and use new words right away in your shift reports, emails and improvement presentations.
Which industrial engineering terms should I learn first?
Start with the words you hear every day on the shop floor: production line, workstation, capacity, throughput, cycle time, lead time, bottleneck, downtime, shift, defect, scrap, rework, inventory and PPE. Then move on to lean, Six Sigma, planning systems, work study and operations research. The terms in this glossary follow the same order, from most to least essential.
Why are there so many Japanese words like kaizen and kanban in English?
Lean manufacturing grew out of the Toyota Production System, and many of its ideas reached Western factories with their Japanese names: kaizen, kanban, gemba, poka-yoke and muda. In English they are used as ordinary nouns (run a kaizen, a kanban card) and are usually written without italics. You can use them with confidence; most international colleagues know them.
How do I say 'endüstri mühendisi' in English, and is it the same as a manufacturing engineer?
The usual term is industrial engineer, and some universities call the field industrial and systems engineering. A manufacturing engineer or process engineer usually focuses on how a specific product is made (machines, tooling, process settings), while an industrial engineer looks at the whole system: flow, layout, capacity, methods, standards and costs. Job titles overlap a lot, so always read the job description.
