Aprototype is an early sample, model, or release of a product built to test a concept or process.[1] It is a term used in a variety of contexts, includingsemantics,design,electronics, andsoftware programming. A prototype is generally used to evaluate a new design to enhance precision by system analysts and users.[2][3] Prototyping serves to provide specifications for a real, working system rather than a theoretical one.[4] Physical prototyping has a long history, andpaper prototyping andvirtual prototyping now extensively complement it. In some design workflow models, creating a prototype (a process sometimes calledmaterialization) is the step between theformalization and theevaluation of an idea.[5]
Aprototype can also mean a typical example of something such as in the use of the derivation'prototypical'.[6] This is a useful term in identifying objects, behaviours and concepts which are considered the accepted norm and is analogous with terms such asstereotypes andarchetypes.
The wordprototype derives from theGreekπρωτότυπονprototypon, "primitive form", neutral ofπρωτότυποςprototypos, "original, primitive", from πρῶτοςprotos, "first" and τύποςtypos, "impression" (originally in the sense of a mark left by a blow, then by a stamp struck by a die (note "typewriter"); by implication a scar or mark; by analogy a shape i.e. a statue, (figuratively) style, or resemblance; a model for imitation or illustrative example—note "typical").[1][7][8]
Prototypes explore different aspects of an intended design:[9]
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In general, the creation of prototypes will differ from creation of the final product in some fundamental ways:
Engineers and prototype specialists attempt to minimize the impact of these differences on the intended role for the prototype. For example, if a visual prototype is not able to use the same materials as the final product, they will attempt to substitute materials with properties that closely simulate the intended final materials.
Engineers and prototyping specialists seek to understand the limitations of prototypes to exactly simulate the characteristics of their intended design.
Prototypes represent some compromise from the final production design. This is due to the skill and choices of the designer(s), and the inevitable inherent limitations of a prototype. Due to differences in materials, processes and design fidelity, it is possible that a prototype may fail to perform acceptably although the production design may have been sound. Conversely, prototypes may perform acceptably but the production design and outcome may prove unsuccessful.
In general, it can be expected that individual prototype costs will be substantially greater than the final production costs due to inefficiencies in materials and processes. Prototypes are also used to revise the design for the purposes ofreducing costs through optimization and refinement.[17]
It is possible to use prototype testing to reduce the risk that a design may not perform as intended, however prototypes generally cannot eliminate all risk.
Building the full design is often expensive and can be time-consuming, especially when repeated several times—building the full design, figuring out what the problems are and how to solve them, then building another full design. As an alternative,rapid prototyping orrapid application development techniques are used for the initial prototypes, which implement part, but not all, of the complete design. This allows designers and manufacturers to rapidly and inexpensively test the parts of the design that are most likely to have problems, solve those problems, and then build the full design.
In technology research, atechnology demonstrator is a prototype serving asproof-of-concept and demonstration model for a new technology or future product, proving its viability and illustrating conceivable applications.
In large development projects, atestbed is a platform and prototype development environment for rigorous experimentation and testing of new technologies, components, scientific theories and computational tools.[18]
With recent advances in computer modeling it is becoming practical to eliminate the creation of a physical prototype (except possibly at greatly reduced scales for promotional purposes), instead modeling all aspects of the final product as acomputer model. An example of such a development can be seen inBoeing 787 Dreamliner, in which the first full sized physical realization is made on the series production line. Computer modeling is now being extensively used in automotive design, both for form (in thestyling and aerodynamics of the vehicle) and in function—especially for improving vehiclecrashworthiness and in weight reduction to improve mileage.
The most common use of the word prototype is a functional, although experimental, version of a non-military machine (e.g., automobiles, domestic appliances, consumer electronics) whose designers would like to have built bymass production means, as opposed to amockup, which is an inert representation of a machine's appearance, often made of some non-durable substance.
An electronics designer often builds the first prototype frombreadboard orstripboard orperfboard, typically using "DIP" packages.
However, more and more often the first functional prototype is built on a "prototypePCB" almost identical to the production PCB, as PCB manufacturing prices fall and as many components are not available inDIP packages, but only available inSMT packages optimized for placing on a PCB.
Builders of military machines and aviation prefer the terms "experimental" and "service test".[19]
Inelectronics,prototyping means building an actual circuit to a theoreticaldesign to verify that it works, and to provide a physical platform for debugging it if it does not. The prototype is often constructed using techniques such aswire wrapping or using abreadboard,stripboard orperfboard, with the result being a circuit that is electrically identical to the design but not physically identical to the final product.[20]
Open-source tools likeFritzing exist to document electronic prototypes (especially the breadboard-based ones) and move toward physical production. Prototyping platforms such asArduino also simplify the task of programming and interacting with amicrocontroller.[21] The developer can choose to deploy their invention as-is using the prototyping platform, or replace it with only the microcontroller chip and the circuitry that is relevant to their product.
A technician can quickly build a prototype (and make additions and modifications) using these techniques, but for volume production it is much faster and usually cheaper to mass-produce customprinted circuit boards than to produce these other kinds of prototype boards. The proliferation of quick-turn PCB fabrication and assembly companies has enabled the concepts of rapid prototyping to be applied to electronic circuit design. It is now possible, even with the smallest passive components and largest fine-pitch packages, to have boards fabricated, assembled, and even tested in a matter of days.Prototype software is often referred to asalpha grade, meaning it is the first version to run. Often only a few functions are implemented, the primary focus of the alpha is to have a functional base code on to which features may be added. Once alpha grade software has most of the required features integrated into it, it becomesbeta software for testing of the entire software and to adjust the program to respond correctly during situations unforeseen during development.[22]
Often the end users may not be able to provide a complete set of application objectives, detailed input, processing, or output requirements in the initial stage. After the user evaluation, another prototype will be built based on feedback from users, and again the cycle returns to customer evaluation. The cycle starts by listening to the user, followed by building or revising a mock-up, and letting the user test themock-up, then back. There is now a new generation of tools calledApplication Simulation Software which help quickly simulate application before their development.[23]
Extreme programming usesiterative design to gradually add one feature at a time to the initial prototype.[24]
In manyprogramming languages, afunction prototype is thedeclaration of asubroutine or function (and should not be confused with software prototyping). This term is ratherC/C++-specific; other terms for this notion aresignature,type andinterface. Inprototype-based programming (a form ofobject-oriented programming), new objects are produced by cloning existing objects, which are called prototypes.[25]
The term may also refer to thePrototype Javascript Framework.
Additionally, the term may refer to theprototype design pattern.
Continuous learning approaches within organizations or businesses may also use the concept of business or process prototypes through software models.
The concept of prototypicality is used to describe how much a website deviates from the expected norm, and leads to a lowering of user preference for that site's design.[26]
Adata prototype is a form offunctionalorworking prototype.[27] The justification for its creation is usually adata migration,data integration or application implementation project and the raw materials used as input are an instance of all the relevant data which exists at the start of the project.
The objectives ofdata prototyping are to produce:
To achieve this, a data architect uses a graphical interface to interactively develop and execute transformation and cleansing rules using raw data. The resultant data is then evaluated and the rules refined. Beyond the obvious visual checking of the dataon-screen by the data architect, the usual evaluation and validation approaches are to usedata profiling software[28] and then to insert the resultant data into a test version of the target application and trial its use.
When developing software or digital tools that humans interact with, a prototype is an artifact that is used to ask and answer a design question. Prototypes provide the means for examining design problems and evaluating solutions.[29]
Human-computer interaction (HCI) practitioners can employ several different types of prototypes:
Inarchitecture, prototyping refers to eitherarchitectural model making (as form ofscale modelling) or as part of aesthetic or materialexperimentation, such as theForty Wall House open source material prototyping centre in Australia.[33][34]
Architects prototype to test ideas structurally, aesthetically and technically. Whether the prototype works or not is not the primary focus: architectural prototyping is the revelatory process through which the architect gains insight.[35]
In the science and practice ofmetrology, aprototype is a human-made object that is used as the standard ofmeasurement of somephysical quantity to base all measurement of that physical quantity against. Sometimes this standard object is called anartifact. In theInternational System of Units (SI), there remains no prototype standardsince May 20, 2019. Before that date, the last prototype used was theinternational prototype of the kilogram, a solidplatinum-iridium cylinder kept at theBureau International des Poids et Mesures (International Bureau of Weights and Measures) inSèvresFrance (a suburb ofParis) that bydefinition was the mass of exactly onekilogram. Copies of this prototype are fashioned and issued to many nations to represent the national standard of the kilogram and are periodically compared to the Paris prototype. Now the kilogram is redefined in such a way that thePlanck constanth is prescribed a value of exactly6.62607015×10−34 joule-second (J⋅s)
Until 1960, themeter was defined by a platinum-iridium prototype bar with two marks on it (that were, by definition, spaced apart by one meter), theinternational prototype of the metre, and in 1983 the meter was redefined to be the distance infree space covered bylight in 1/299,792,458 of asecond (thusdefining the speed of light to be 299,792,458 meters per second).
In many sciences, from pathology to taxonomy,prototype refers to a disease, species, etc. which sets a good example for the whole category. In biology,prototype is the ancestral or primitive form of a species or other group; an archetype.[36] For example, theSenegal bichir is regarded as the prototypes of its genus,Polypterus.
Makers of scale models, especially railway, aircraft, ship and military modellers, customarily useprototype to meanfull size,[37] such as in "The length of this model is not true to prototype".
