Prototyping

From Wikipedia, the free encyclopedia

Prototyping is the process of quickly putting together a working model (a prototype) in order to test various aspects of a design, illustrate ideas or features and gather early user feedback. Prototyping is often treated as an integral part of the system design process, where it is believed to reduce project risk and cost. Often one or more prototypes are made in a process of incremental development where each prototype is influenced by the performance of previous designs, in this way problems or deficiencies in design can be corrected. When the prototype is sufficiently refined and meets the functionality, robustness, manufacturability and other design goals, the product is ready for production.

Advantages and disadvantages

Advantages of prototyping

• Prototypes can be easily changed
• May provide the proof of concept 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

Disadvantages of prototyping

• User’s expectation on prototype may be above its performance^[clarify]
• Possibility of causing systems to be left unfinished^{[citation needed]}
• Possibility of implementing systems before they are ready.^[clarify]
• Producer might produce a system inadequate for overall organization needs
• Producer might get too attached to it (might cause legal involvement)^{[verification needed]}
• Often lack flexibility^{[citation needed]}
• Not suitable for large applications
• Project management difficulties^{[verification needed]}

Software prototyping

Main article: software prototyping

The prototyping model is a software development process that begins with requirements collection, followed by prototyping and user evaluation. 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.

In the mid-1980s, prototyping became seen as the solution to the problem of requirements analysis within software engineering. Prototypes are mock-ups of the screens of an application which allow users to visualize the application that is not yet constructed. Prototypes help users get an idea of what the system will look like, and make it easier for users to make design decisions without waiting for the system to be built. When they were first introduced the initial results were considered amazing. Major improvements in communication between users and developers were often seen with the introduction of prototypes. Early views of the screens led to fewer changes later and hence reduced overall costs considerably.

However, over the next decade, while proving a useful technique, it did not solve the requirements problem:

• Managers, once they see the prototype, often have a hard time understanding that the finished design will not be produced for some time.
• Designers often feel compelled to use the patched-together prototype code in the real system, because they are afraid to 'waste time' starting again.
• Prototypes principally help with design decisions and user interface design. However, they can not tell what the requirements were originally.
• Designers and end users can focus too much on user interface design and too little on producing a system that serves the business process.

Electronics prototyping

In electronics, 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 or using veroboard or breadboard, that create an electrically correct circuit, but one that is not physically identical to the productionized product.

A technician can build a prototype (and make additions and modifications) much quicker with these techniques — however, it is much faster and usually cheaper to mass produce custom printed circuit boards 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.

Rapid Electronics prototyping

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 smalled passive components and largest fine-pitch packages, to have boards fabbed and parts assembled in a matter of days.

See also

• Productionisation
• Rapid prototyping
• Rapid Application Development
• Software Prototyping

References

• Haag, Stephen; Maeve Cummings; Donald J. McCubbrey; Alain Pinsonneault; and Richard Donovan. Management Information Systerms: For the Information Age. 3rd Canadian ed. New York: McGraw-Hill Ryerson, 2006.