Manufacturing Terms Every Mechanical Engineer Should Know


Manufacturing is an industry filled with jargon and abbreviations. More experienced engineers can easily navigate the acronym-filled waters, but if you’re just getting started we’ve put together this glossary to common manufacturing terms that every mechanical engineer or product designer should know. 

Build Phase Manufacturing Terms

Prototype: An engineering-quality sample build of a product, typically intended to test high-risk aspects of the design.

Pre-EVT: Pre-EVT stands for Pre-Engineering Validation Test. Pre-EVT is generally the first full official build of a product and often lacks the full polish of a finished product. As this is a prototype build, engineers are usually still working out the last bit of major functionality in the design. A Pre-EVT unit will be considered looks-like/feels-like but is lacking the full polish of a finished product. 

EVT: EVT stands for Engineering Validation Test. The main purpose during this build phase is to select the production intent design, and then manufacture a number of units (100 to 1000) with that design to identify all of the issues that need to be fixed. This is also the least expensive time to introduce solutions to issues that need to be fixed – so it’s important to find every potential cause now as it will grow more costly at each stage. 

DVT: DVT stands for Design Validation Test. The main purpose during this build phase is to verify mass production yields with one, production-worthy design and to qualify the first tool for every part. Typical quantities range from 300 to 2000.

PVT: PVT stands for Production Validation Test. The main purpose during this build phase is to verify mass production yields at mass production speeds and to qualify additional tools needed to support mass quantities for early ramp up of manufacturing. Typical quantities range from 1k to 20k. This is the last step in the development process before mass production.

MP: Mass Production is the final step in getting the product out the door. The product is validated and the assembly line is validated. This is where units get shipped to customers (and is also the most expensive time to introduce solutions to root causes.)

Basic Manufacturing Terms

AOI: AOI stands for Automated Optical Inspection. AOI refers to a class of product that combines a camera and some processing to inspect units for visually identifiable issues. Typically, AOI systems are entirely on premises (i.e. no connection to the outside world) and based on traditional, rules-based CV algorithms, though the big players in this market, Keyence and Cognex, have released ML solutions recently.

Box-build – Also called systems integration, box-build is the assembly work, other than printed circuit board (PCB) production, involving enclosure fabrication, installation of sub-assemblies and components, and installation and routing of cabling or wire harnesses.

BOM: BOM stands for Bill of Materials. A BOM is the list of parts or items that make up a product assembly. A complete product BOM often includes subassemblies, which may represent different steps in the assembly process. For instance, a lawn mower may include the following elements: a handle assembly, a metal deck assembly, a control assembly, a motor and a blade assembly.

CA: CA stands for corrective actions, which are measures taken by the manufacturer to introduce and validate solutions to defects, failure modes, or anomalies. 

CAD: CAD stands for Computer Aided Design. CAD tools are used to do complex tasks and generate complex designs that otherwise would have taken weeks to months to validate and test.

Config / Configuration: A configuration is a “recipe” on the Bill of Materials for a specific group of units. For example, in the same build, you might build a configuration of black units and a configuration of white units.  You might build a configuration that contains certain vendors or variations of components (also see, Stuff/Stuffed).  Configurations usually have names, sometimes as simple as “A”, “B”, etc — and they are defined as columns on a Build Matrix.

CM: CM stands for contract manufacturer. A CM is a separately owned factory that works with companies to make their products. Services can range from PCB assembly all the way to final assembly and pack.

Daily Mode:  If you are on Daily Mode on a problem, it means you are having once (or even twice) daily meetings between the individual engineers working to solve the problem and multiple layers of management, often up to and including a VP, SVP, or even C-level executive.  It’s incredibly stressful because as an engineer, you split your time between trying to fix the problem and providing regular, detailed updates to executives which can directly impact your progress to a solution.  It’s common to end up in Daily Mode for an issue that blocks build, ramp, or production velocity.

FA: FA stands for failure analysis, the process engineers take to determine the root cause behind a failure mode. Visit our blog to learn more about the FA process.

EFFA: EFFA stands for Early Field Failure Analysis. In the first 6-8 weeks after shipping, manufacturing teams capture returned units back from the field in order to conduct failure analysis on them and try to implement changes to improve the product.

Encapsulant: This is generally a glue-like material (or a spray) that is applied to an electronic board or electronic joint (like a solder joint) to enclose the joint and protect it from moisture.  Sometimes encapsulant can be used to increase the strength of an electronic joint as well.  These materials can have UV-tracer, which means they will fluoresce under black lights, enabling humans to better see them.  Instrumental stations can be outfitted with black lights for this purpose.  Encapsulation inspection is a good application for Instrumental.

EOL: EOL stands for end-of-life and is often used by OEMs on products that they will no longer market, sell, or update – often after a newer model is released. 

FATP: FATP stands for Final Assembly, Test and Pack. FATP is the process of assembling, often by hand, a product from different parts. This process is often done in an assembly line where at each station the operator has only one function (i.e. adding one piece, gluing one component to another, etc.)

GR&R: GR&R stands for Gauge Reliability and Repeatability. GR&R is the process in which to determine if a component of a system will produce reliable results in all the expected operating conditions.

IQC: IQC stands for Incoming Quality Control. IQC is the process of ensuring quality in a product is up to par with expectations. This can be done in the form of different stations on an assembly line or disassembling a fully packed product to ensure assembly procedures have been followed.

IPQC: IPQC stands for In-Process Quality Control. IPQC happens during the process of assembly on the line. This can often be a line worker checking for defects caused by the assembly process at a particular point on the assembly line.

NPI: NPI stands for new product introduction. The market launch or commercialization of a new product. NPI takes place at the end of a successful product development project.

NPD: NPD stands for new product development, and is commonly referred to as simply “product development”. NPD is the overall process of conceptualizing, designing, planning and commercializing a new product. 

NPD process: A disciplined and defined set of tasks and steps that describe the normal means by which a company repetitively converts embryonic ideas into salable products or services.

Off-the-Shelf: Describes an item that is procured from a supplier as-is, with no modifications.

PDE: PDE stands for product design engineer. The PDE is responsible for the overall design of the product as well as finding, fixing, and monitoring potential defects and anomalies across the program. 

PLM: PLM stands for product lifecycle management. PLM is the management of the product record, including bills of materials, specifications, revisions and changes, from prototype through end-of-life.

ODM: ODM stands for Original Design Manufacturers. ODMs are often paid to engineer a product from concept and deliver all the way to production. ODMs are also often contract manufacturers.

OEM: OEM stands for original equipment manufacturer. The original manufacturer of a product that may be sold or marketed by another company.

OQC: OQC stands for Outgoing Quality Control. OQC is often referring to the process that occurs to check for functionality and quality before they’re shipped to your factory.

QC: QC stands for Quality Control. QC is the process done at the factory to ensure the product you’re assembling is free of defects. This often relates to the fixtures and test equipment.

QA: QA stands for Quality Assurance. QA is the process done before a product is set to ramp. Things like electrical validation and reliability are quality assurance procedures.

SOP: SOP stands for Standard Operating Procedure. In a manufacturing environment, an SOP is the documented workflow for any standard practice.

RC: RC stands for Root Cause – the specific factor that caused a nonconformance that causes a failure mode or performance issue in the field. 

Rel: Rel stands for Reliability, as in reliability testing (environmental, mechanical, chemical, strife, etc). Download our reliability test kit for more information. 

Post-rel: Post-rel stands for Post-Reliability Testing, such as functional tests you might do after a reliability test to see if anything broke, or “post-rel FA” failure analysis.

SMA: SMA stands for Surface Mount Assembly. SMA is a method for producing electronic circuits in which the components are mounted or placed directly onto the surface of printed circuit boards (PCBs).

Stuff/stuffed: Stuffed is a word used to mean “assembled into” and generally is used in the context of making a differentiation between multiple different versions of the same part, such as from different vendors, or different designs. 

Integrated Circuit (Chip) Manufacturing Terms

Assembly House: An Assembly House is where a PCB will get assembled. The assembly is often done by large and expensive pick and place machines and extensive ovens (for melting the solder between components and the PCB).

BGA: A ball grid array is a type of surface-mount packaging (a chip carrier) used for integrated circuits. BGA packages are used to permanently mount devices such as microprocessors.

Fab House: A fabrication house manufacturers printed circuit boards. They often take Gerber files or ODB++ files to help translate a “virtually” designed PCB to the real thing.

Footprint: A footprint is the shape of the bare copper required to connect to the pins of an IC or chip. 

ICs: ICs stands for Integrated Circuits. Integrated Circuits house complex circuitry that is implemented on the silicon wafer level. This enables engineers to design products that are extremely small but have a huge amount of functionality.

Note: ICs are also commonly known as chips.

Layout: Layout is the process of creating the design files for a PCB.

MLB: The main logic board is the PCB that often houses the “brains” of a product. It is often the PCB with the most components on it.

PCB: PCB stands for Printed Circuit Boards. These are the green boards that you can find in almost every type of electronics.

PCBA: PCBA stands for Printed Circuit Board Assembly, which is a printed circuit board populated with components.

Routing: Routing often refers to the making of connections between components in a circuit.

SoC: SoC stands for System on a Chip. An SoC is often several separate integrated circuits placed on chip. A good example of an SoC is a microprocessor that has an embedded 2.4Ghz radio.

SMT: SMT stands for Surface Mount Technology. SMT refers to the types of components that can be attached to a PCB. Surface mount components do not require holes and, for the most part, reside on one side of a PCB. The picture of the assembled PCB above has only surface mount components.

Other Technical Terms:

AML: AML stands for Approved Manufacturer List. An AML is a set of approved relationships between manufacturer parts and a company’s internally defined parts. Each relationship links a manufacturer’s part number to an internal part number and results from the R&D team’s identifying the third-party parts that can be used to satisfy the manufacturing demand for the internal part. All approved AML parts for each internal part can share a single inventory bin.

APQP: APQP stands for Advanced Product Quality Planning. APQP is a framework of procedures used to develop products in the automotive industry.

ATP: ATP stands for Acceptance Test Plan. ATP is often the document that tests need to be run at a factory to ensure that the product shipped to customers will operate within specifications.

AVL: AVL stands for Approved Vendor List. An AVL is a list of all the vendors or suppliers approved by a company as sources from which to purchase materials.

Build Matrix: This is the recipe list for all of the Configurations of units that will be built in the build.  It’s usually a spreadsheet, where the rows contain all of the possible variations of different parts and components, and the columns indicate whether that part is “stuffed” (included) or not.

CAPA: CAPA stands for Corrective Action/Protective Action. A good manufacturing practice (GMP) concept, in which product failures are investigated in an attempt to correct their current occurrence (corrective action) and/or prevent similar occurrences in the future (protective action).

CAR: CAR stands for Corrective Action Request, a change request documenting a critical problem with a product.

CMF: CMF stands for Color, Material, and Finish.

Change Management: Change management is the process of creating, reviewing and gaining formal approval for engineering change requests, change orders and change notifications.

Change Request: A Change Request outlines a problem and proposes an action to address the problem. Some types of change requests are: DCR (document change request), ECR (engineering change request), FFR (field failure request), MCR (manufacturing change request) and SCAR (supplier corrective action request).

Child Item: A Child Item is an item that appears in the BOM of another item is said to be a child of that item.

Compliance: The practice of tracking whether or not a product complies with government-imposed regulations or a company’s self-imposed standards. Some types of compliance requirements are environmental requirements and medical device regulations.

Compliance Mark: A physical mark listed on a product or its packaging to show the product’s compliance with a specific requirement (e.g. UL, CE, CCC, FCC and VCCI ).

DCR: DCR stands for Document Change Request. This is a change request which details a problem with a document, specification or SOP (standard operating procedure) and proposes a change to fix it.

DHF: DHF stands for Design History File. A DHF is a collection of records that describes the design history of a finished medical device. The design history file documents the design decisions made throughout the development of the device including sign-off events, change information, meeting notes, test data and reports and evidence that the device has been scrutinized carefully against design and performance specifications. The design history file provides the chronology of the design, including previous revision information and phase gate details. Source: 21 CFR Part 820 Sec 820.3

DHR: DHR stands for Device History Record. A DHR is a collection of records containing the production history of a medical device. This includes the serial and lot numbers of the devices produced, and any complaints or issues that are lodged against particular devices. In addition, it may include CAPA records describing investigations, corrective and preventative actions and details about how any complaints were addressed.

DMR: DMR stands for Device Master Record. DMR is a collection of records that contain the procedures and specifications for a finished medical device. This includes the BOM for the device, product and material specifications, packaging and assembly instructions. Post processing, cleaning and sterilization requirements, hardware and software specifications and source code may be included too, depending on the type of device. The DMR provides all information required to correctly build the current production revision of the device. Source: 21 CFR Part 820 Sec 820.3 and 820.181

DOE: DOE stands for Design of Experiment. A DOE is the document often used to describe how an experiment will be run. It includes all the necessary steps, parameters, etc. to ensure that said experiment produces valid and useful results.

DFM: DFM stands for Design for Manufacturability. DFM is the process, often done by mechanical engineers, to ensure that the product being designed can be assembled efficiently and without complex machinery (as much as possible).

Document Control: The function of managing and controlling product documentation. This includes maintaining and properly distributing product files while following revision control procedures.

EBOM: EBOM stands for Engineering Bill of Materials, which is a BOM organized according to CAD/EDA tool and engineers’ preferences and processes. The EBOM represents only the physical product being “engineered,” not the packaging or manufacturing consumables. It often includes items for a single engineering discipline only, summarizing or excluding items from other disciplines.

ECN: ECN stands for Engineering Change Notice. An ECN is an official notice that a change has been approved. Many companies use a formal ECN to ensure their CMs (contract manufacturers) and other manufacturing partners are building the right thing.

ECO: ECO stands for Engineering Change Order. An ECO is documentation that outlines a proposed change to a design, lists the product or part(s) that would be affected and requests review and approval from the individuals who would be impacted or charged with implementing the change. ECOs are used to make modifications to components, assemblies, associated documentation and other types of product information.

ECP: ECP stands for Engineering Change Proposal. An ECP is a management tool used to propose a configuration change to a Configuration Item (CI) and its government-baselined performance requirements and configuration documentation during an acquisition program.

ECR: ECR stands for Engineering Change Request, which is a change request listing proposed improvements or problems with components or assemblies. An ECR may be a precursor to an ECO.

EDA: EDA stands for Electronic Design Automation. EDA includes software tools used to develop integrated circuits and systems. Some examples of EDA software include Altium Designer by Altium, DxDatabook by Mentor Graphics and OrCAD Capture CIS by Cadence.

EE: EE stands for Electrical Engineer/Engineering. An EE is someone who develops circuits/PCBs that are put inside products.

EP1/2/3: EP stands for Engineering Pilot, which is another name for a development build.

EPM: EPM stands for Engineering Project Manager. EPMs help coordinate engineering efforts to ensure things go smoothly from concept to launch. They play an integral role in ensuring a successful development, ramp and launch of a product. Contrary to their title, they often don’t manage people, they manage the program/project: their authority is limited but they are superconnectors in the organization.

ERP: ERP stands for Enterprise Resource Planning. An ERP is a business strategy used to keep track of activities like purchasing, inventory and order tracking. Some examples of ERP software systems include NetSuite and Expandable.

FFR: FFR stands for Field Failure Request. This is a change request which details a problem with the product as observed in the field.

FCT: FTC stands for functional test. For large production volumes, this is often done when MLBs are still panelized. They are placed in a test jig and then tested all at once. It is often good practice to do as many tests as possible at the FCT level to reduce fallout later in the assembly process.

FFF: FFF stands for Form, Fit and Function. FFA is a description of an item’s identifying characteristics. Form refers to the shape, size, dimensions, mass, weight and other visual parameters that uniquely distinguish an item. Fit is the ability of an item to physically interface with, interconnect with or become an integral part of another item. Function is the action or actions that an item is designed to perform. Changes in an item’s form, fit or function are typically considered significant enough to merit a new item number.

Family tooling: A specially designed mold base that allows for the use of interchangeable inserts and cavities in it. This provides exceptional economy and fast delivery without sacrificing quality. This could also refer to one mold that shares two or more different parts in the core and cavity for injection molding.

GMP: GMP stands for Good Manufacturing Practice. GMP is a set of guidelines for how to manage each aspect of production and testing that can impact the quality of a product. GMPs are part of a quality system covering the manufacture and testing of active pharmaceutical ingredients, diagnostics, foods, pharmaceutical products and medical devices. 

Item: A part, process or document included in a manufacturer’s product record.

Item Master: A list of all components that a manufacturer buys, builds or assembles into its products. The item master includes information like the size, shape, material, manufacturer, manufacturer part number and vendor for each component.

ITAR: ITAR stands for International Traffic in Arms Regulations. ITAR is a set of United States government import and export regulations. Manufacturers in the aerospace and defense industry and others that provide products to the U.S. military and government often have to comply with ITAR.

JIT – (Just in time) A strategy used to monitor inventory levels with the goal of reducing inventory and associated carrying costs.

Kanban – A scheduling system that advises manufacturers what to produce, when to produce and how much to produce. Devised by Toyota, the approach is based on demand creating a “pull.” Inventory is replenished only when visual cues like an empty bin or cart show that it’s needed. This differs from a “push” inventory system where deliveries are planned in advance based on a master schedule.

LIDAR: A detection system that works on the principle of RADAR, but uses laser light.  It is generally thought this is what will make autonomous driving work.  Instrumental does not use LIDAR, but we can be applied to LIDAR products.

ME: Mechanical Engineer/Engineering

Made-to-Spec – Describes an item that is made to a company’s specifications internally or by a supplier.

MBOM – (Manufacturing bill of materials) A BOM organized into subassemblies that reflect the manufacturing process. The MBOM represents the physical product, packaging and included documentation. It contains all components required to build the product — made-to-spec, off-the-shelf, mechanical, electrical, software and firmware.

MCAD Software: MCAD stands for Mechanical Computer Aided Design. MCAD software is used by mechanical engineers to develop concepts and designs of mechanical systems. Some examples of MCAD software include SolidWorks, Pro/ENGINEER by PTC, Solid Edge by Siemens and AutoCAD by Autodesk.

MCO: MCO stands for Manufacturing Component Outline. MCO is the physical shape, or a drawing that represents a part or component.

MCR: MCR stands for Manufacturing Change Request. MCR is a change request used to propose a manufacturing change that does not require a design change to an item. An example is a change to the approved manufacturer list (AML).

Manufacturing Deviation: A temporary change in production or a manufacturing procedure. An example is the use of a substitute part. Deviations may be planned or unplanned.

MES: MES stands for Manufacturing Execution System. An MES is a system that controls and manages production on the factory floor with the goal of reducing the total time needed to produce an order. Often called “Shop Floor”.

Markup:  A document, such as a redlined drawing, that has annotations indicating recommended changes to a file.

MRD: MRD stands for Marketing Requirements Document. An MRD is a document created by marketing to help determine the functionality and usability of a product from a customer perspective. This document can then be transformed into a PRD (Product Requirements Document) by the engineering team.

Multi-level BOM: This is a BOM that captures how multiple sub-assemblies come together to produce a final product. It can be visualized as a nested list whose parts or items are listed in two or more levels of detail.

MWI: MWI stands for Manufacturing Work Instructions. This includes information and directions on how to perform a manufacturing task.

PRQ: PRQ stands for Post Ramp Qualification. This is when a product design engineer implements a new design change when a product is already in mass production

PD: PD stands for Product Design. PD often refers to the mechanical engineers working on a product. They are responsible for all the aspects related to the development and fabrication of the physical components of a product.

POR: POR stands for Per Order Request or Plan of Record. POR is often used to indicate if a certain function or physical component of a product is close if not exactly what will be shipped to a customer. For example, if my circuit board has a switch on it, the switch will be POR if that switch will be implemented in the final design of the product that will ship to customers.

Parent Item: This describes an item that contains another item (i.e. a child item) in its bill of materials. An assembly-component or assembly-subassembly relationship can be described as a parent-child relationship.

Part Name: A unique name assigned to a part.

Part Number: A unique numerical value assigned to a part.

PDM System: PDM stands for Product Data Management. A PDM system is also referred to as a “work in progress (WIP) vault” or file repository. A PDM system is used to hold mechanical CAD files, including parts and assembly models as well as drawing files.

PDX: PDX stands for Product Data Exchange – an iNEMI (international electronics manufacturing initiative) standard. PDX is an open XML (eXtensible markup language)-based standard allowing organizations to access their data directly, even using their own XML-based applications/tools. PDX is commonly used throughout the design chain and the supply chain to deliver the multi-level BOM, AML, recent change history and supporting design files zipped in a single file. There are several free PDX viewers on the market.

Procurement Type: This describes how a part is bought or made, typically OTS (off-the-shelf) or MTS (made-to-specification). In some cases the part may be built in house or outsourced from a vendor.

Product Record: This is a general term that describes all design, manufacturing, quality, sales and repair information about a product.

PRD: PRD stands for Product Requirements Document. As stated above, a PRD often can be the outcome of a well thought out MRD. In most cases, the PRD is developed in conjunction with marketing. If you’re developing a product and at most you do something make sure you write a PRD.

PRS: PRS stands for Product Requirement Specification. A product requirement specification is an extension of the PRD which includes acceptable parameters for different functionality. These specifications are much tighter compared to the PRD as to account for fluctuations in production, etc. (i.e. this document is commonly driven more by engineering with the PRD in mind)

QMS: QMS stands for Quality Management System. QMS documents all aspects of a company’s design and operational controls, including monitoring, issue reporting, continuous improvements and training, in order to ensure that product design and manufacturing have statistically in-control repeatable product deliveries. It can also be a set of controls for other departments, such as human resources, finance/accounting and corporate reporting.

RF: RF stands for Radio Frequency. RF waves are everywhere! In regards to a product, RF often refers to the radios that are often integrated. Radios include, but are not limited to, Bluetooth Low Energy, Wifi, Zigbee, GSM, etc.

RFQ: RFQ stands for Request For Quotation. This is the formal process where companies will request a quotation of a specific part or assembly. RFQs are often used to determine how much a product will cost to be made at a factory.

Redline: Redline Is the marking of an assembly drawing or bill of materials (BOM) to indicate a modification.

Red rabbit: A red rabbit is an intentionally defective unit (usually made) used to train systems to catch similar defects in the future.  We sometimes use these to accelerate value creation from Instrumental.

Reference Designator: A reference designator is an alphanumeric code (e.g., R17) that gives the physical location of a component on a PCB (printed circuit board). A code for each part is listed on the bill of materials and physically printed on the PCB so the manufacturer knows where to place all the components.

Requirement: References the standards against which companies measure their products. A requirement could be a government regulation regarding environmental or safety concerns, or any internal standard.

Revision: A snapshot of a product, part, process, program, design or document at any moment in its development.

Revision Control: The process of tracking and documenting changes to a product, part, process, program, design or document.

RMA: RMA stands for Return Material Authorization. An RMA is a financial and work order tracking key to identify a returned item’s origination. This is used in a transaction in which a customer returns goods to a manufacturer, often to have them repaired or replaced.

SRM: SRM stands for Safety Risk Management. SRM refers to the identification, analysis and elimination (and/or mitigation to an. acceptable or tolerable level) of any threat, hazard, or risk to an organization.

SCAR: SCAR stands for Supplier Corrective Action Request. This is a change request describing an issue with a part, process or component from a supplier and asking for a resolution. A SCAR sometimes includes details about how the complaint should be addressed.

Scrubbing: Used in the phrase “scrubbing a BOM” to describe the process of confirming that all aspects of a bill of materials (BOM) are documented accurately in the appropriate control systems and verifying that the BOM represents a manufacturable assembly.

Shop Floor: See MES above.

Single-Level BOM: A bill of materials that lists all the parts or items in a product assembly one level below the top-level assembly. 

TTM: TTM stands for Time to Market. This is the period of time from development of a product concept to availability of the finished product. It starts when a development project has been agreed to and resources have been committed and ends when the final product is shipped to customers.

UOM: UOM stands for Unit of Measure. A UOM describes how manufacturers use or buy a part. The most common UOM is “each,” but standard measures like feet, inches, pints, drops, box, etc. can also be used.

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