Manufacturing glossary

5S

A method for organising a workplace so that problems are visible. The five Japanese words are seiri, seiton, seiso, seiketsu and shitsuke, usually translated as sort, set in order, shine, standardise and sustain.

5 Whys

A root cause technique: ask “why” repeatedly until you reach the cause that, if fixed, stops the problem returning. ASQ credits Sakichi Toyoda with developing it.

8D

Eight Disciplines, a structured team method for solving a problem and stopping it recurring, widely used for customer complaints in the automotive supply chain. Customers often ask for an “8D report”.

Andon

A visual signal, typically a light or a board, that shows the status of a machine or line and calls for help when there is a problem.

APQP

Advanced Product Quality Planning. The automotive industry’s structured process for planning a new part from concept to production. One of the automotive core tools published by AIAG.

AQL

Acceptance quality limit. The quality level used to choose a sampling plan for inspecting a lot, as in ISO 2859-1. It is not permission to ship that share of defects.

Availability

In OEE, run time divided by planned production time. It falls when the machine is stopped by breakdowns, changeovers or waiting. See the OEE guide.

BOM

Bill of materials. The list of raw materials, components and quantities needed to make one unit of a product.

Bottleneck

The step in a process with the least capacity. It sets the output of the whole process, so an hour lost there is an hour lost for the plant.

Changeover

The work of switching a machine from one product to the next, measured from the last good part of the old job to the first good part of the new one. Also called setup.

Control plan

A document that lists, for each process step, what is checked, how, how often and what to do when a check fails. Required in automotive supply.

Cp and Cpk

Process capability indices. Cp compares the tolerance width with the process spread. Cpk also accounts for how well the process is centred. See the formulas.

Cycle time

The time required to make one part or complete one operation, as measured on the floor. Ideal cycle time is the fastest the machine can achieve for that part.

DPMO

Defects per million opportunities. Defects divided by units times opportunities per unit, times one million.

Downtime

Time when a machine was planned to run but did not. Planned stops such as breaks are usually reported separately.

FIFO

First in, first out. Using or shipping the oldest stock first, so material does not age in the stores.

First pass yield (FPY)

The share of units that pass a process step correctly the first time, with no scrap and no rework.

FMEA

Failure Mode and Effects Analysis. A structured way to list how a design or process could fail, how serious each failure would be, and what will prevent or detect it. An automotive core tool.

GRN

Goods receipt note. The record made when purchased material arrives, used to update stock and to match against the purchase order and the supplier’s invoice.

IATF 16949

The quality management system standard for the automotive supply chain, published by the International Automotive Task Force. It is used together with ISO 9001, not on its own.

ISO 9001

The international standard for quality management system requirements, published by ISO. Certificates are issued by accredited certification bodies, not by ISO itself.

Job card

The record of what happened at one operation of a work order: machine, operator, times, quantities and stops. A template is here.

Kaizen

Continuous, incremental improvement involving the people who do the work.

Kanban

A signal, originally a card, that tells the previous operation to supply more material only when it is needed.

Lead time

The time a product takes to move through the whole process from start to finish, including waiting. In everyday use it also means the time from order to delivery.

MES

Manufacturing execution system. Software that manages and records production on the floor: dispatching jobs, tracking output, quality and stops. It sits between the machines and the ERP.

MRP

Material requirements planning. Calculating what material is needed, and when, from the production plan, the bill of materials and current stock.

MSA

Measurement Systems Analysis. Studies that check whether a gauge and the people using it measure consistently enough to be trusted, such as a gauge R&R study. An automotive core tool.

MTBF

Mean time between failures. Total operating time divided by the number of failures.

MTTR

Mean time to repair. Total repair time divided by the number of repairs.

MTConnect

An open, royalty-free standard that gives manufacturing equipment data a common vocabulary so software can read it the same way from different machines. See machine data collection.

OEE

Overall equipment effectiveness. Availability × Performance × Quality: the share of planned production time spent making good parts at full speed. See the OEE calculator.

OPC UA

OPC Unified Architecture. A platform-independent standard for exchanging industrial data, published by the OPC Foundation and as IEC 62541.

PDCA

Plan, do, check, act. A four-step cycle for improvement, also called the Shewhart cycle or the Deming cycle.

Performance

In OEE, how fast the machine ran compared with its ideal cycle time: ideal cycle time times total count, divided by run time.

PLC

Programmable logic controller. The industrial computer that controls a machine or a line.

Poka-yoke

Mistake-proofing. A device or design that makes an error impossible, or makes it obvious the moment it happens.

PPAP

Production Part Approval Process. The package of evidence an automotive supplier submits to show that its process can make a part to the customer’s requirements. An automotive core tool.

Predictive maintenance

Maintenance done when measured condition, such as vibration, temperature or current, shows that a failure is developing.

Preventive maintenance

Maintenance done on a schedule, by time or by usage, to reduce the chance of a breakdown.

Quality

In OEE, good count divided by total count, where a good part is one that was right the first time.

Rework

Correcting a defective part so that it meets the requirement. A reworked part is not a good part for first pass yield or OEE.

Routing

The sequence of operations, machines and standard times needed to make a part.

Scrap

Material or parts that cannot be used or corrected and are discarded.

Seven wastes

The seven kinds of waste identified by Taiichi Ohno of Toyota: overproduction, waiting, transport, overprocessing, inventory, motion and defects. An eighth, unused talent, is often added.

Six big losses

The six causes of lost equipment effectiveness in TPM: equipment failure, setup and adjustments, idling and minor stops, reduced speed, process defects and reduced yield.

SMED

Single-Minute Exchange of Die. A method, credited to Shigeo Shingo, for cutting changeover time. “Single-minute” means a single-digit number of minutes, under ten.

SOP

Standard operating procedure. The written, agreed way of doing a task.

SPC

Statistical Process Control. Using control charts to tell normal process variation from a real change that needs action. An automotive core tool.

Takt time

Available production time divided by customer demand: the pace at which units must be finished to meet demand.

TEEP

Total effective equipment performance. OEE multiplied by utilisation, measured against all calendar time.

TPM

Total Productive Maintenance. An approach in which operators and maintenance staff share responsibility for keeping equipment effective. OEE is its main measure.

Traceability

The ability to follow a part back to its material batch, machine, operator and inspection records, and forward to the customer who received it.

WIP

Work in progress. Material that has been issued to production but is not yet finished goods.

Work order

The instruction to make a given quantity of a part by a given date. Also called a production order.

The formulas and definitions on this page are the standard published ones. These are the references we checked them against. If you find an error, write to deep@deda.systems and we will correct it.