Design prototyping in its broader definition comprises the actions to make, test and analyze a prototype, a model, or a mock-up according to one or various purposes in different stages of the design process. Other definitions consider prototyping as the methods or techniques for making a prototype (e.g., rapid prototyping techniques), or a stage in the design process (prototype development, prototype, or prototyping). The concept of prototyping in design disciplines’ literature is also related to the concepts of experimentation (i.e., an iterative problem-solving process of trying, failing and improving), and Research through Design (RtD) (i.e., designers make a prototype with the purpose of conducting research and generating knowledge while trying it, rather than aiming to improving it to become a final product).
However, one of the first documented uses of the term prototyping linked to a design process appears in 1983 in “A systematic look at prototyping in the field of information systems and software development”. The work of Floyd was inspired by the discussions among the scholars who were preparing the Working Conference on Prototyping. It focuses on prototype as a process, rather than the artefact and how prototyping could be applied to the full solution (or product) or parts of it seeking to improve the final output. Although this work was not developed within the design discipline, it provides a comprehensive characterization of prototyping by defining its steps, purposes and strategies. Moreover, it serves as a referent to further studies of design prototyping.
Later, around the year of 1990, the availability of methods for rapidly manufacturing models and prototypes stimulated the publication of a great body of literature dedicated to rapid prototyping techniques and technologies (e.g., 3D printing). Technologies for additive manufacturing (i.e., adding material) or subtractive manufacturing (i.e, removing material by machining) together with the use of software for computer-aided design (CAD), leveraged prototype building but also the fabrication of products in limited numbers.
Along the years, further efforts have been dedicated to characterizing prototyping in design disciplines in the fields of interaction design, experience design, product design and service design, as well as in product-design-related fields such as engineering/mechanical design. In 2000, designers from IDEO described experience prototyping, introducing types of design representations and methods that allow to simulate aspects of an interaction that people experience by themselves.
Prototyping is developed in an iterative cycle of making, testing and analyzing which allows to examine dimensions of a solution before its future implementation, anticipating to possible issues and improving them earlier in the process.
Preparation: to decide about the aims of prototyping, define questions and assumptions that are going to be examined, identify the participants of the prototyping sessions and the dimensions of the prototype that are going to be tested.
Making: some or various dimensions will be represented in a prototype (e.g., material, form or function) employing what is appropriate depending on the purpose.
Testing: the prototyping session develops in a defined setup with certain characteristics of space and environment and will follow a method to gather feedback.
Analyzing: the results of the testing will be integrated into the solution and updated in the following prototype versions.
Characteristics of Prototyping
To prepare for prototyping, some aspects need to be decided. For this purpose, it is useful to individualize and consider various characteristics that will allow identifying how prototyping should be developed according to the design needs.
Evaluation: prototyping can be developed to evaluate qualitatively potential solutions or part of them. For instance, it can aid to examine the functionality or the experience of testing it with the future user. The feedback gathered from the evaluation can validate (or not) previous assumptions, help to narrow down alternatives and make decisions about the solution.
Experimentation: prototyping leads to run an experiment on a prototype to examine in a more technical and quantitative manner the feasibility, efficiency, and specifications of a solution.
Learning: prototyping is used to gather knowledge about the performance of a prototype and learn about how the solution could work in relation to the user needs.
Evolution: prototyping could be developed to incrementally improve a prototype until it is refined to get the final solution. This may lead to prototype rapid tooling being employed to emulate more realistic production intent materials and wear functionality.
More recent developments in software now allow prototype models to be ordered online and delivered in a matter of days, sometimes even hours.
Very often prototypes are required in relatively large quantities for product and crash testing and some common processes to achieve this are vacuum casting and RIM moulding in various grades of PU.
Highly complex geometric parts can now also be achieved by 3D printing and, where production intent materials are a must, by using production methods such as spark erosion, wire cutting, laser cutting, water jet cutting, prototype press and extrusion tools and 5 axis cnc machining.