Prototype

Prototype

Discussion
Ask a question about 'Prototype'
Start a new discussion about 'Prototype'
Answer questions from other users
Full Discussion Forum
 
Encyclopedia
A prototype is an early sample or model built to test a concept or process or to act as a thing to be replicated or learned from.

The word prototype derives from the Greek
Greek language
Greek is an independent branch of the Indo-European family of languages. Native to the southern Balkans, it has the longest documented history of any Indo-European language, spanning 34 centuries of written records. Its writing system has been the Greek alphabet for the majority of its history;...

 πρωτότυπον (prototypon), "primitive form", neutral of πρωτότυπος (prototypos), "original, primitive", from πρῶτος (protos), "first" and τύπος (typos), "impression".

Semantics


In semantics
Semantics
Semantics is the study of meaning. It focuses on the relation between signifiers, such as words, phrases, signs and symbols, and what they stand for, their denotata....

, prototypes or proto instances combine the most representative attributes of a category. Prototypes are typical instances of a category that serve as benchmarks against which the surrounding, less representative.

Design and modeling


In many fields, there is great uncertainty as to whether a new design will actually do what is desired. New designs often have unexpected problems. A prototype is often used as part of the product design process to allow engineers and designers the ability to explore design alternatives, test theories and confirm performance prior to starting production of a new product. Engineers use their experience to tailor the prototype according to the specific unknowns still present in the intended design. For example, some prototypes are used to confirm and verify consumer interest in a proposed design whereas other prototypes will attempt to verify the performance or suitability of a specific design approach.

In general, an iterative series of prototypes will be designed, constructed and tested as the final design emerges and is prepared for production. With rare exceptions, multiple iterations of prototypes are used to progressively refine the design. A common strategy is to design, test, evaluate and then modify the design based on analysis of the prototype.

In many products it is common to assign the prototype iterations Greek letters. For example, a first iteration prototype may be called an "Alpha" prototype. Often this iteration is not expected to perform as intended and some amount of failures or issues are anticipated. Subsequent prototyping iterations (Beta, Gamma, etc.) will be expected to resolve issues and perform closer to the final production intent.

In many product development organizations, prototyping specialists are employed - individuals with specialized skills and training in general fabrication techniques that can help bridge between theoretical designs and the fabrication of prototypes.

Basic prototype categories


There is no general agreement on what constitutes a "prototype" and the word is often used interchangeably with the word "model" which can cause confusion. In general, "prototypes" fall into five basic categories:

Proof-of-Principle Prototype (Model) (in electronics sometimes built on a breadboard
Breadboard
A breadboard is a construction base for prototyping of electronics. The term is commonly used to refer to solderless breadboard ....

). A Proof of concept
Proof of concept
A proof of concept or a proof of principle is a realization of a certain method or idea to demonstrate its feasibility, or a demonstration in principle, whose purpose is to verify that some concept or theory that has the potential of being used...

  prototype is used to test some aspect of the intended design without attempting to exactly simulate the visual appearance, choice of materials or intended manufacturing process. Such prototypes can be used to "prove" out a potential design approach such as range of motion, mechanics, sensors, architecture, etc. These types of models are often used to identify which design options will not work, or where further development and testing is necessary.

Form Study Prototype (Model). This type of prototype will allow designers to explore the basic size, look and feel of a product without simulating the actual function or exact visual appearance of the product. They can help assess ergonomic factors and provide insight into visual aspects of the product's final form. Form Study Prototypes are often hand-carved or machined models from easily sculpted, inexpensive materials (e.g., urethane foam), without representing the intended color, finish, or texture. Due to the materials used, these models are intended for internal decision making and are generally not durable enough or suitable for use by representative users or consumers.

User Experience Prototype (Model). A User Experience Model invites active human interaction and is primarily used to support user focused research. While intentionally not addressing possible aesthetic treatments, this type of model does more accurately represent the overall size, proportions, interfaces, and articulation of a promising concept. This type of model allows early assessment of how a potential user interacts with various elements, motions, and actions of a concept which define the initial use scenario and overall user experience. As these models are fully intended to be used and handled, more robust construction is key. Materials typically include plywood, REN shape, RP processes and CNC machined components. Construction of user experience models is typically driven by preliminary CAID/CAD which may be contructed from scratch or with methods such as industrial CT scanning
Industrial CT Scanning
Industrial CT scanning is a process which uses X-ray equipment to produce three-dimensional representations of components both externally and internally. Industrial CT scanning has been used in many areas of industry for internal inspection of components...

.

Visual Prototype (Model) will capture the intended design aesthetic and simulate the appearance, color and surface textures of the intended product but will not actually embody the function(s) of the final product. These models will be suitable for use in market research, executive reviews and approval, packaging mock-ups, and photo shoots for sales literature.

Functional Prototype (Model) (also called a working prototype) will, to the greatest extent practical, attempt to simulate the final design, aesthetics, materials and functionality of the intended design. The functional prototype may be reduced in size (scaled down) in order to reduce costs. The construction of a fully working full-scale prototype and the ultimate test of concept, is the engineers' final check for design flaws and allows last-minute improvements to be made before larger production runs are ordered.

Differences between a prototype and a production design


In general, prototypes will differ from the final production variant in three fundamental ways:

Materials. Production materials may require manufacturing processes involving higher capital costs than what is practical for prototyping. Instead, engineers or prototyping specialists will attempt to substitute materials with properties that simulate the intended final material.

Processes. Often expensive and time consuming unique tooling is required to fabricate a custom design. Prototypes will often compromise by using more variable processes, repeatable or controlled methods; substandard, inefficient, or substandard technology sources; or insufficient testing for technology maturity.

Lower fidelity. Final production designs often require extensive effort to capture high volume manufacturing detail. Such detail is generally unwarranted for prototypes as some refinement to the design is to be expected. Often prototypes are built using very limited engineering detail as compared to final production intent, which often uses statistical process controls and rigorous testing.

By RDM

Characteristics and limitations of prototypes


Engineers and prototyping specialists seek to understand the limitations of prototypes to exactly simulate the characteristics of their intended design. A degree of skill and experience is necessary to effectively use prototyping as a design verification tool.

It is important to realize that by their very definition, prototypes will represent some compromise from the final production design. Due to differences in materials, processes and design fidelity, it is possible that a prototype may fail to perform acceptably whereas the production design may have been sound. A counter-intuitive idea is that prototypes may actually perform acceptably whereas the production design may be flawed since prototyping materials and processes may occasionally outperform their production counterparts.

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 of reducing costs through optimization and refinement.

It is possible to use prototype testing to reduce the risk that a design may not perform acceptably, however prototypes generally cannot eliminate all risk. There are pragmatic and practical limitations to the ability of a prototype to match the intended final performance of the product and some allowances and engineering judgement are often required before moving forward with a production design.

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" or "rapid 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.

This counter-intuitive idea —that the quickest way to build something is, first to build something else— is shared by scaffolding
Scaffolding
Scaffolding is a temporary structure used to support people and material in the construction or repair of buildings and other large structures. It is usually a modular system of metal pipes or tubes, although it can be from other materials...

 and the telescope rule.

Modern trends


With the 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 a computer model. An example of such a development can be seen in the Boeing 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 the styling and aerodynamics
Automotive design
Automotive design is the profession involved in the development of the appearance, and to some extent the ergonomics, of motor vehicles or more specifically road vehicles. This most commonly refers to automobiles but also refers to motorcycles, trucks, buses, coaches, and vans...

 of the vehicle) and in function — especially for improving vehicle crashworthiness
Crashworthiness
Crashworthiness is the ability of a structure to protect its occupants during an impact. This is commonly tested when investigating the safety of aircraft and vehicles. Depending on the nature of the impact and the vehicle involved, different criteria are used to determine the crashworthiness of...

 and in weight reduction to improve mileage.

Mechanical and electrical engineering


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 by mass production
Mass production
Mass production is the production of large amounts of standardized products, including and especially on assembly lines...

 means, as opposed to a mockup
Mockup
In manufacturing and design, a mockup, or mock-up, is a scale or full-size model of a design or device, used for teaching, demonstration, design evaluation, promotion, and other purposes...

, 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 from breadboard
Breadboard
A breadboard is a construction base for prototyping of electronics. The term is commonly used to refer to solderless breadboard ....

 or stripboard
Stripboard
Stripboard is a widely-used type of electronics prototyping board characterized by a 0.1 inch regular grid of holes, with wide parallel strips of copper cladding running in one direction all the way across one side of the board...

 or perfboard
Perfboard
Perfboard is a material for prototyping electronic circuits. It is a thin, rigid sheet with holes pre-drilled at standard intervals across a grid, usually a square grid of 2.54 mm spacing. These holes are ringed by round or square copper pads...

, typically using "DIP" packages.

However, more and more often the first functional prototype is built on a "prototype PCB
Printed circuit board
A printed circuit board, or PCB, is used to mechanically support and electrically connect electronic components using conductive pathways, tracks or signal traces etched from copper sheets laminated onto a non-conductive substrate. It is also referred to as printed wiring board or etched wiring...

" almost identical to the production PCB, as PCB manufacturing prices fall and as many components are not available in DIP
Dual in-line package
In microelectronics, a dual in-line package is an electronic device package with a rectangular housing and two parallel rows of electrical connecting pins. The package may be through-hole mounted to a printed circuit board or inserted in a socket.A DIP is usually referred to as a DIPn, where n is...

 packages, but only available in SMT
Surface-mount technology
Surface mount technology is a method for constructing electronic circuits in which the components are mounted directly onto the surface of printed circuit boards . An electronic device so made is called a surface mount device...

 packages optimized for placing on a PCB.

Builders of military machines and aviation prefer the terms "experimental" and "service test".

Electronics prototyping


In electronics
Electronics
Electronics is the branch of science, engineering and technology that deals with electrical circuits involving active electrical components such as vacuum tubes, transistors, diodes and integrated circuits, and associated passive interconnection technologies...

, prototyping means building an actual circuit to a theoretical design 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 as wire wrap
Wire wrap
Wire wrap is a technology used to assemble electronics. It is a method to construct circuit boards without having to make a printed circuit board. Wires can be wrapped by hand or by machine, and can be hand-modified afterwards. It was popular for large-scale manufacturing in the 60s and early 70s,...

 or using veroboard or breadboard
Breadboard
A breadboard is a construction base for prototyping of electronics. The term is commonly used to refer to solderless breadboard ....

, that create an electrically correct circuit, but one that is not physically identical to the final product.

Open-source tools exist to document electronic prototypes (especially the breadboard-based ones) and move forward toward production such as Fritzing
Fritzing
Fritzing is an open source software initiative to support designers and artists ready to move from physical prototyping to actual product. It was developed at the University of Applied Sciences of Potsdam.- Goals :...

 and Arduino
Arduino
Arduino is an open-source single-board microcontroller, descendant of the open-source Wiring platform, designed to make the process of using electronics in multidisciplinary projects more accessible. The hardware consists of a simple open hardware design for the Arduino board with an Atmel AVR...

.

A technician can build a prototype (and make additions and modifications) much more quickly with these techniques —however, it is much faster and usually cheaper to mass produce custom printed circuit board
Printed circuit board
A printed circuit board, or PCB, is used to mechanically support and electrically connect electronic components using conductive pathways, tracks or signal traces etched from copper sheets laminated onto a non-conductive substrate. It is also referred to as printed wiring board or etched wiring...

s than these other kinds of prototype boards. This is for the same reasons that writing a poem is fastest by hand for one or two, but faster by printing press if you need several thousand copies.

The proliferation of quick-turn pcb fab companies and quick-turn pcb assembly houses 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 fabbed and parts assembled in a matter of days.

Computer programming/computer science


In many programming language
Programming language
A programming language is an artificial language designed to communicate instructions to a machine, particularly a computer. Programming languages can be used to create programs that control the behavior of a machine and/or to express algorithms precisely....

s, a function prototype
Function prototype
A function prototype in C, Perl or C++ is a declaration of a function that omits the function body but does specify the function's return type, name, arity and argument types...

is the declaration
Declaration (computer science)
In programming languages, a declaration specifies the identifier, type, and other aspects of language elements such as variables and functions. It is used to announce the existence of the element to the compiler; this is important in many strongly-typed languages that require variables and their...

 of a subroutine
Subroutine
In computer science, a subroutine is a portion of code within a larger program that performs a specific task and is relatively independent of the remaining code....

 or function. (This term is rather C
C (programming language)
C is a general-purpose computer programming language developed between 1969 and 1973 by Dennis Ritchie at the Bell Telephone Laboratories for use with the Unix operating system....

/C++
C++
C++ is a statically typed, free-form, multi-paradigm, compiled, general-purpose programming language. It is regarded as an intermediate-level language, as it comprises a combination of both high-level and low-level language features. It was developed by Bjarne Stroustrup starting in 1979 at Bell...

-specific; other terms for this notion are signature, type and interface.) In prototype-based programming
Prototype-based programming
Prototype-based programming is a style of object-oriented programming in which classes are not present, and behavior reuse is performed via a process of cloning existing objects that serve as prototypes. This model can also be known as classless, prototype-oriented or instance-based programming...

 (a form of object-oriented programming
Object-oriented programming
Object-oriented programming is a programming paradigm using "objects" – data structures consisting of data fields and methods together with their interactions – to design applications and computer programs. Programming techniques may include features such as data abstraction,...

), new objects are produced by cloning existing objects, which are called prototypes.

The term may also refer to the Prototype Javascript Framework
Prototype Javascript Framework
The Prototype JavaScript Framework is a JavaScript framework created by Sam Stephenson in February 2005 as part of the foundation for Ajax support in Ruby on Rails. It is implemented as a single file of JavaScript code, usually named prototype.js...

.

Additionally, the term may refer to the prototype
Prototype pattern
The prototype pattern is a creational design pattern used in software development when the type of objects to create is determined by a prototypical instance, which is cloned to produce new objects...

 design pattern.

Prototype software is often referred to as alpha 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 becomes beta software for testing of the entire software and to adjust the program to respond correctly during situations unforeseen during development.

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 the mock-up, then back. There is now a new generation of tools called Application Simulation Software which help quickly simulate application before their development.

Extreme programming
Extreme Programming
Extreme programming is a software development methodology which is intended to improve software quality and responsiveness to changing customer requirements...

 uses iterative design
Iterative design
Iterative design is a design methodology based on a cyclic process of prototyping, testing, analyzing, and refining a product or process. Based on the results of testing the most recent iteration of a design, changes and refinements are made. This process is intended to ultimately improve the...

 to gradually add one feature at a time to the initial prototype.

Continuous learning approaches within organizations or businesses may also use the concept of business or process prototypes through software models.

Prototype, software prototyping and alpha software


"Prototype" and "alpha" are often used interchangeably in the realm of software development. When referring the hardware development, the term "prototype" is exclusively used. Both refer to an early stage development stage. It is common for prototype to refer to an initial version which demonstrates the very basic functionality of the development subject.

For further clarification on the subject prototypes, we can look at this comparison. Note that every project has different stages of development and these represents only a common breakdown.
Hardware Software Explanation
Concept Concept Idea
Proof of Concept Proof of Concept Possible ways to show that the theory behind the concept is functional. May not even work at all, but just show whether or not it is possible to create.
Prototype Alpha First version of product meant for showreels and testing purposes ONLY. Also here it might not work as a program or unit, but it is to give the visual presentation of a possibly real product.
Work In Progress Work In Progress Several different stages of development.
Functional prototype Beta Software that is almost complete, but still needs some fixing, but in general a testing product that is to be treated as not done. Feedback on the product is often gathered from a random selection of people (or people who specifically signed up as beta testers).
Pilot Release candidate Release candidates are often used by Microsoft as a stage in the development of a new operating system (for example, Windows Longhorn (Vista) and Windows Blackcomb (Seven)) to show the masses that the product is within the final stages of development.
Final Product Final Product Product that has been tested both within closed test groups and open test groups. May still contain a few small issues, but in general it is a complete working product that will work as it is made for the majority of the users. Measures like "patches" and "bug fixes" are created to fix software products, and "repair", "swaps" and/or "recall and destruction" of hardware is set in motion to save the reputation of the companies.


But remember that new, updated versions of the products may also be distributed, ex. videogames will get bug fixes and possibly extra content which will be packed as a new, same, but "fixed" product, under a slightly different name like "Game of the Year" or "Special Edition"(not to be confused with an eventual "Special Edition" that may have been released when the game first launched, containing extra stuff from or for the game as promotion), and hardware might be modified and released under the name of the company that modifies it. Like Shelby is to Mustang, AMG is to Mercedes and Top Secret is to other cars.

This is just a more commonly used way of the word prototype(as to not being software), but in general alpha and prototype is the same thing.

Nowadays, the difference between software prototype
Software Prototype
A Software Prototype is a high-fidelity simulation of the software before its first version is made. It is used to simulate the final design, materials and functionalities of the program. Wrongly associated with mockups or wireframes, a prototype is a fully operational version of an application...

 and Alpha versions increase when the prototypes are built with an agile prototyping
Agile software development
Agile software development is a group of software development methodologies based on iterative and incremental development, where requirements and solutions evolve through collaboration between self-organizing, cross-functional teams...

 tool and the final software is developed with any coding language.

Data prototyping


A data prototype is a form of functional or working prototype. The justification for its creation is usually a data 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 of data prototyping are to produce:
  • A set of data cleansing and transformation rules which have been seen to produce data which is all fit for purpose.
  • A dataset which is the result of those rules being applied to an instance of the relevant raw (source) data.

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 data on-screen by the data architect, the usual evaluation and validation approaches are to use Data profiling
Data profiling
Data profiling is the process of examining the data available in an existing data source and collecting statistics and information about that data...

 software and then to insert the resultant data into a test version of the target application and trial its use.

Scale modeling


In the field of scale model
Scale model
A scale model is a physical model, a representation or copy of an object that is larger or smaller than the actual size of the object, which seeks to maintain the relative proportions of the physical size of the original object. Very often the scale model is used as a guide to making the object in...

ing (which includes model railroading, vehicle modeling, airplane modeling, military modeling, etc.), a prototype is the real-world basis or source for a scale model—such as the real EMD GP38-2
EMD GP38-2
An EMD GP38-2 is a four-axle diesel-electric locomotive of the road switcher type built by General Motors Electro-Motive Division. Part of the EMD Dash 2 line, the GP38-2 was an upgraded version of the earlier GP38...

 locomotive—which is the prototype of Athearn
Athearn
Athearn is a United States manufacturer of model railroad equipment, produced and distributed by American hobby manufacturer Horizon Hobby, Inc. of Champaign, Illinois, USA.-History:...

's (among other manufacturers) locomotive model. Technically, any non-living object can serve as a prototype for a model, including structures, equipment, and appliances, and so on, but generally prototypes have come to mean full-size real-world vehicles including automobiles (the prototype 1957 Chevy has spawned many models), military equipment (such as M4 Shermans, a favorite among US Military modelers), railroad equipment, motor trucks, motorcycles, and space-ships (real-world such as Apollo/Saturn Vs, or the ISS).

There is debate whether 'fictional' or imaginary items can be considered prototypes (such as Star Wars or Star Trek starships, since the feature ships themselves are models or CGI-artifacts); however, humans and other living items are never called prototypes, even when they are the basis for models and dolls (especially - action figures).

As of 2005, conventional rapid prototype machines cost around £25,000.

Metrology


In the science and practice of metrology
Metrology
Metrology is the science of measurement. Metrology includes all theoretical and practical aspects of measurement. The word comes from Greek μέτρον , "measure" + "λόγος" , amongst others meaning "speech, oration, discourse, quote, study, calculation, reason"...

, a prototype is a human-made object that is used as the standard of measurement
Measurement
Measurement is the process or the result of determining the ratio of a physical quantity, such as a length, time, temperature etc., to a unit of measurement, such as the metre, second or degree Celsius...

 of some physical quantity
Physical quantity
A physical quantity is a physical property of a phenomenon, body, or substance, that can be quantified by measurement.-Definition of a physical quantity:Formally, the International Vocabulary of Metrology, 3rd edition defines quantity as:...

 to base all measurement of that physical quantity against. Sometimes this standard object is called an artifact. In the International System of Units
International System of Units
The International System of Units is the modern form of the metric system and is generally a system of units of measurement devised around seven base units and the convenience of the number ten. The older metric system included several groups of units...

 (SI), the only prototype remaining in current use is the International Prototype Kilogram, a solid platinum
Platinum
Platinum is a chemical element with the chemical symbol Pt and an atomic number of 78. Its name is derived from the Spanish term platina del Pinto, which is literally translated into "little silver of the Pinto River." It is a dense, malleable, ductile, precious, gray-white transition metal...

-iridium
Iridium
Iridium is the chemical element with atomic number 77, and is represented by the symbol Ir. A very hard, brittle, silvery-white transition metal of the platinum family, iridium is the second-densest element and is the most corrosion-resistant metal, even at temperatures as high as 2000 °C...

 cylinder kept at the Bureau International des Poids et Mesures (International Bureau of Weights and Measures) in Sèvres
Sèvres
Sèvres is a commune in the southwestern suburbs of Paris, France. It is located from the centre of Paris.The town is known for its porcelain manufacture, the Manufacture nationale de Sèvres, making the famous Sèvres porcelain, as well as being the location of the International Bureau of Weights...

 France
France
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...

 (a suburb of Paris
Paris
Paris is the capital and largest city in France, situated on the river Seine, in northern France, at the heart of the Île-de-France region...

) that by definition
Definition
A definition is a passage that explains the meaning of a term , or a type of thing. The term to be defined is the definiendum. A term may have many different senses or meanings...

 is the mass of exactly one kilogram
Kilogram
The kilogram or kilogramme , also known as the kilo, is the base unit of mass in the International System of Units and is defined as being equal to the mass of the International Prototype Kilogram , which is almost exactly equal to the mass of one liter of water...

. 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.

Until 1960, the meter
Metre
The metre , symbol m, is the base unit of length in the International System of Units . Originally intended to be one ten-millionth of the distance from the Earth's equator to the North Pole , its definition has been periodically refined to reflect growing knowledge of metrology...

 was defined by a platinum-iridium prototype bar with two scratch marks on it (that were, by definition, spaced apart by one meter), the International Prototype Metre, and in 1983 the meter was redefined to be the distance in free space covered by light
Speed of light
The speed of light in vacuum, usually denoted by c, is a physical constant important in many areas of physics. Its value is 299,792,458 metres per second, a figure that is exact since the length of the metre is defined from this constant and the international standard for time...

 in 1/299,792,458 of a second
Second
The second is a unit of measurement of time, and is the International System of Units base unit of time. It may be measured using a clock....

 (thus defining the speed of light to be 299,792,458 meters per second).

It is widely believed that the kilogram prototype standard will be replaced by a definition of the kilogram that will define another physical constant
Physical constant
A physical constant is a physical quantity that is generally believed to be both universal in nature and constant in time. It can be contrasted with a mathematical constant, which is a fixed numerical value but does not directly involve any physical measurement.There are many physical constants in...

 (likely either Planck's constant or the elementary charge
Elementary charge
The elementary charge, usually denoted as e, is the electric charge carried by a single proton, or equivalently, the absolute value of the electric charge carried by a single electron. This elementary charge is a fundamental physical constant. To avoid confusion over its sign, e is sometimes called...

) to a defined numerical value, thus obviating the need for the prototype and removing the possibility of the prototype (and thus the standard and definition of the kilogram) changing very slightly over the years because of loss or gain of atoms.

Sciences


In many sciences, from pathology to taxonomy, prototype refers to a disease, species, etc. which sets a good example for the whole category. For example, the vaccina virus and Senegal bichir are regarded as the prototypes of their respective species.

Advantages of prototyping

  • May provide the proof of concept
    Proof of concept
    A proof of concept or a proof of principle is a realization of a certain method or idea to demonstrate its feasibility, or a demonstration in principle, whose purpose is to verify that some concept or theory that has the potential of being used...

     necessary to attract funding
  • Early visibility of the prototype gives users an idea of what the final system looks like
  • Encourages active participation among users and producer
  • Enables a higher output for user
  • Cost effective (Development costs reduced).
  • Increases system development speed
  • Assists to identify any problems with the efficacy of earlier design, requirements analysis
    Requirements analysis
    Requirements analysis in systems engineering and software engineering, encompasses those tasks that go into determining the needs or conditions to meet for a new or altered product, taking account of the possibly conflicting requirements of the various stakeholders, such as beneficiaries or users...

    and coding activities
  • Helps to refine the potential risks associated with the delivery of the system being developed
  • Various aspects can be tested and quicker feedback can be got from the user
  • Helps to deliver the product in quality easily
  • User interaction available during development cycle of prototype

Disadvantages of prototyping

  • Producer might produce a system inadequate for overall organization needs
  • User can get too involved whereas the program can not be to a high standard
  • Structure of system can be damaged since many changes could be made
  • Producer might get too attached to it (might cause legal involvement)
  • Not suitable for large applications
  • Over long periods, can cause loss in consumer interest and subsequent cancellation due to a lack of a market (for commercial products)
  • May slow the development process, if there are large number of end users to satisfy.