Tolerance coning is the engineering discipline of creating a budget of all tolerances that potentially add/subtract to affect adequacy of a particular parameter. This is particularly critical where stages of design/manufacture precede test/use.
For example, when setting a test limit for a measurement on each manufactured item of some type, to assure that no bad items are shipped, the limit must be tighter than the requirement to allow for the worst case sum of measurement inaccuracies (e.g. equipment, test fixture etc.). The design of the item thus has to take into account not only the product requirement but also the test tolerances. The buildup of this budget is tolerance coning.
A test fixture is something used to consistently test some item, device, or piece of software. Test fixtures can be found when testing electronics, software and physical devices.
Electronics engineers intuitively do tolerance coning and tend to formalise it for critical parameters. However it is also relevant to other engineering disciplines.
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Tolerance or toleration is the state of tolerating, or putting up with, conditionally.
Automotive engineering, along with aerospace engineering and naval architecture, is a branch of vehicle engineering, incorporating elements of mechanical, electrical, electronic, software, and safety engineering as applied to the design, manufacture and operation of motorcycles, automobiles, and trucks and their respective engineering subsystems. It also includes modification of vehicles. Manufacturing domain deals with the creation and assembling the whole parts of automobiles is also included in it. The automotive engineering field is research -intensive and involves direct application of mathematical models and formulas. The study of automotive engineering is to design, develop, fabricate, and test vehicles or vehicle components from the concept stage to production stage. Production, development, and manufacturing are the three major functions in this field.
Taguchi methods are statistical methods, or sometimes called robust design methods, developed by Genichi Taguchi to improve the quality of manufactured goods, and more recently also applied to engineering, biotechnology, marketing and advertising. Professional statisticians have welcomed the goals and improvements brought about by Taguchi methods, particularly by Taguchi's development of designs for studying variation, but have criticized the inefficiency of some of Taguchi's proposals.
Geometric dimensioning and tolerancing (GD&T) is a system for defining and communicating engineering tolerances. It uses a symbolic language on engineering drawings and computer-generated three-dimensional solid models that explicitly describe nominal geometry and its allowable variation. It tells the manufacturing staff and machines what degree of accuracy and precision is needed on each controlled feature of the part. GD&T is used to define the nominal geometry of parts and assemblies, to define the allowable variation in form and possible size of individual features, and to define the allowable variation between features.
Engineering tolerance is the permissible limit or limits of variation in:
Thiele/Small parameters are a set of electromechanical parameters that define the specified low frequency performance of a loudspeaker driver. These parameters are published in specification sheets by driver manufacturers so that designers have a guide in selecting off-the-shelf drivers for loudspeaker designs. Using these parameters, a loudspeaker designer may simulate the position, velocity and acceleration of the diaphragm, the input impedance and the sound output of a system comprising a loudspeaker and enclosure. Many of the parameters are strictly defined only at the resonant frequency, but the approach is generally applicable in the frequency range where the diaphragm motion is largely pistonic, i.e. when the entire cone moves in and out as a unit without cone breakup.
Reliability engineering is a sub-discipline of systems engineering that emphasizes dependability in the lifecycle management of a product. Dependability, or reliability, describes the ability of a system or component to function under stated conditions for a specified period of time. Reliability is closely related to availability, which is typically described as the ability of a component or system to function at a specified moment or interval of time.
In general go/no go testing refers to a pass/fail test principle using two boundary conditions or a binary classification. The test is passed only when the Go condition is met and also the No go condition fails.
NEBS (Network Equipment-Building System) describes the environment of a typical United States RBOC Central Office. NEBS is the most common set of safety, spatial and environmental design guidelines applied to telecommunications equipment in the United States. It is an industry requirement, but not a legal requirement.
Integrated logistic support (ILS) is an integrated and iterative process for developing materiel and a support strategy that optimizes functional support, leverages existing resources, and guides the system engineering process to quantify and lower life cycle cost and decrease the logistics footprint, making the system easier to support. Although originally developed for military purposes, it is also widely used in commercial product support or customer service organisations.
Design for manufacturability is the general engineering practice of designing products in such a way that they are easy to manufacture. The concept exists in almost all engineering disciplines, but the implementation differs widely depending on the manufacturing technology. DFM describes the process of designing or engineering a product in order to facilitate the manufacturing process in order to reduce its manufacturing costs. DFM will allow potential problems to be fixed in the design phase which is the least expensive place to address them. Other factors may affect the manufacturability such as the type of raw material, the form of the raw material, dimensional tolerances, and secondary processing such as finishing.
ANOVA gauge repeatability and reproducibility is a measurement systems analysis technique that uses an analysis of variance (ANOVA) random effects model to assess a measurement system.
Performance engineering encompasses the techniques applied during a systems development life cycle to ensure the non-functional requirements for performance will be met. It may be alternatively referred to as systems performance engineering within systems engineering, and software performance engineering or application performance engineering within software engineering.
Nanometrology is a subfield of metrology, concerned with the science of measurement at the nanoscale level. Nanometrology has a crucial role in order to produce nanomaterials and devices with a high degree of accuracy and reliability in nanomanufacturing.
STEP-NC is a machine tool control language that extends the ISO 10303 STEP standards with the machining model in ISO 14649, adding geometric dimension and tolerance data for inspection, and the STEP PDM model for integration into the wider enterprise. The combined result has been standardized as ISO 10303-238.
Tolerance analysis is the general term for activities related to the study of potential accumulated variation in mechanical parts and assemblies. Its methods may be used on other types of systems subject to accumulated variation, such as mechanical and electrical systems. Engineers analyze tolerances for the purpose of evaluating geometric dimensioning and tolerancing (GD&T). Methods include 2D tolerance stacks, 3D Monte Carlo simulations, and datum conversions.
Tensile testing, also known as tension testing, is a fundamental materials science and engineering test in which a sample is subjected to a controlled tension until failure. Properties that are directly measured via a tensile test are ultimate tensile strength, breaking strength, maximum elongation and reduction in area. From these measurements the following properties can also be determined: Young's modulus, Poisson's ratio, yield strength, and strain-hardening characteristics. Uniaxial tensile testing is the most commonly used for obtaining the mechanical characteristics of isotropic materials. Some materials use biaxial tensile testing.
Process Validation is the analysis of data gathered throughout the design and manufacturing of a product in order to confirm that the process can reliably output products of a determined standard. Regulatory authorities like EMA and FDA have published guidelines relating to process validation. The purpose of process validation is to ensure varied inputs lead to consistent and high quality outputs. Process validation is an ongoing process that must be frequently adapted as manufacturing feedback is gathered. End-to-end validation of production processes is essential in determining product quality because quality cannot always be determined by finished-product inspection. Process validation can be broken down into 3 steps: process design, process qualification, and continued process verification.
Design for Inspection (DFI) is an engineering principle that proposes that inspection methods and measurement instruments used to certify manufacturing conformity, should be considered early in the design of products. Production processes should be designed in such a way that features of the product are easy to inspect with readily available measurement instruments, and so that measurement uncertainty is considered in the tolerance that are applied. The concept can be applied in almost all engineering disciplines. DFI describes the process of designing or engineering a product in order to facilitate the measurement in order to reduce the overall costs of manufacturing and delivering products that satisfy customers.