Iterative Design
   HOME

TheInfoList



OR:

Iterative design is a
design A design is a plan or specification for the construction of an object or system or for the implementation of an activity or process or the result of that plan or specification in the form of a prototype, product, or process. The verb ''to design'' ...
methodology based on a cyclic process of
prototyping A prototype is an early sample, model, or release of a product built to test a concept or process. It is a term used in a variety of contexts, including semantics, design, electronics, and software programming. A prototype is generally used to ...
,
testing An examination (exam or evaluation) or test is an educational assessment intended to measure a test-taker's knowledge, skill, aptitude, physical fitness, or classification in many other topics (e.g., beliefs). A test may be administered verba ...
, analyzing, and refining a product or process. Based on the results of testing the most recent
iteration Iteration is the repetition of a process in order to generate a (possibly unbounded) sequence of outcomes. Each repetition of the process is a single iteration, and the outcome of each iteration is then the starting point of the next iteration. ...
of a design, changes and refinements are made. This process is intended to ultimately improve the quality and functionality of a design. In iterative design, interaction with the designed system is used as a form of research for informing and evolving a project, as successive versions, or iterations of a design are implemented.


History

Iterative design has long been used in engineering fields. One example is the plan–do–check–act cycle implemented in the 1960s. Most
New product development In business and engineering, new product development (NPD) covers the complete process of bringing a new product (business), product to market, renewing an existing product or introducing a product in a new market. A central aspect of NPD is prod ...
or existing product improvement programs have a checking loop which is used for iterative purposes.
DMAIC DMAIC (an acronym for Define, Measure, Analyze, Improve and Control) (pronounced də-MAY-ick) refers to a data-driven improvement cycle used for improving, optimizing and stabilizing business processes and designs. The DMAIC improvement cycle is t ...
uses the Six Sigma framework and has such a checking function.


Object-Oriented Programming

Iterative design is connected with the practice of
object-oriented programming Object-oriented programming (OOP) is a programming paradigm based on the concept of "objects", which can contain data and code. The data is in the form of fields (often known as attributes or ''properties''), and the code is in the form of pr ...
, and the phrase appeared in computer science literature as early as 1990. The idea has its roots in
spiral development The spiral model is a risk-driven software development process model. Based on the unique risk patterns of a given project, the spiral model guides a team to adopt elements of one or more process models, such as Iterative and incremental developm ...
, conceived of by
Barry Boehm Barry William Boehm (May 16, 1935 – August 20, 2022) was an American software engineer, distinguished professor of computer science, industrial and systems engineering; the TRW Professor of Software Engineering; and founding director of the Cen ...
.


Iterative design process

The iterative design process may be applied throughout the
new product development In business and engineering, new product development (NPD) covers the complete process of bringing a new product (business), product to market, renewing an existing product or introducing a product in a new market. A central aspect of NPD is prod ...
process. However, changes are easiest and less expensive to implement in the earliest stages of development. The first step in the iterative design process is to develop a
prototype A prototype is an early sample, model, or release of a product built to test a concept or process. It is a term used in a variety of contexts, including semantics, design, electronics, and Software prototyping, software programming. A prototyp ...
. The prototype should be evaluated by a
focus group A focus group is a group interview involving a small number of demographically similar people or participants who have other common traits/experiences. Their reactions to specific researcher/evaluator-posed questions are studied. Focus groups are ...
or a group not associated with the product in order to deliver non-biased opinions. Information from the focus group should be synthesized and incorporated into the next iteration of the design. The process should be repeated until user issues have been reduced to an acceptable level.


Application: Human computer interfaces

Iterative design is commonly used in the development of human computer interfaces. This allows designers to identify any usability issues that may arise in the user interface before it is put into wide use. Even the best usability experts cannot design perfect user interfaces in a single attempt, so a usability engineering lifecycle should be built around the concept of iteration. The typical steps of iterative design in user interfaces are as follows: # Complete an initial interface design # Present the design to several test users # Note any problems had by the test user # Refine interface to account for/fix the problems # Repeat steps 2-4 until user interface problems are resolved Iterative design in user interfaces can be implemented in many ways. One common method of using iterative design in computer software is
software testing Software testing is the act of examining the artifacts and the behavior of the software under test by validation and verification. Software testing can also provide an objective, independent view of the software to allow the business to apprecia ...
. While this includes testing the product for functionality outside of the user interface, important feedback on the interface can be gained from subject testing early versions of a program. This allows software companies to release a better quality product to the public, and prevents the need of product modification following its release. Iterative design in online (website) interfaces is a more continual process, as website modification, after it has been released to the user, is far more viable than in software design. Often websites use their users as test subjects for interface design, making modifications based on recommendations from visitors to their sites.


Iterative design use

Iterative design is a way of confronting the reality of unpredictable user needs and behaviors that can lead to sweeping and fundamental changes in a design. User testing will often show that even carefully evaluated ideas will be inadequate when confronted with a user test. Thus, it is important that the flexibility of the iterative design's implementation approach extends as far into the system as possible. Designers must further recognize that user testing results may suggest radical change that requires the designers to be prepared to completely abandon old ideas in favor of new ideas that are more equipped to suit user needs. Iterative design applies in many fields, from making knives to rockets. As an example consider the design of an
electronic circuit An electronic circuit is composed of individual electronic components, such as resistors, transistors, capacitors, inductors and diodes, connected by conductive wires or traces through which electric current can flow. It is a type of electrical ...
that must perform a certain task, and must ultimately fit in a small space on a
circuit board A printed circuit board (PCB; also printed wiring board or PWB) is a medium used in Electrical engineering, electrical and electronic engineering to connect electronic components to one another in a controlled manner. It takes the form of a L ...
. It is useful to split these independent tasks into two smaller and simpler tasks, the functionality task, and the space and weight task. A
breadboard A breadboard, solderless breadboard, or protoboard is a construction base used to build semi-permanent prototypes of electronic circuits. Unlike a perfboard or stripboard, breadboards do not require soldering or destruction of tracks and are ...
is a useful way of implementing the electronic circuit on an interim basis, without having to worry about space and weight. Once the circuit works, improvements or incremental changes may be applied to the breadboard to increase or improve functionality over the original design. When the design is finalized, one can set about designing a proper circuit board meeting the space and weight criteria. Compacting the circuit on the circuit board requires that the wires and components be juggled around without changing their electrical characteristics. This juggling follows simpler rules than the design of the circuit itself, and is often
automated Automation describes a wide range of technologies that reduce human intervention in processes, namely by predetermining decision criteria, subprocess relationships, and related actions, as well as embodying those predeterminations in machines ...
. As far as possible
off the shelf Off-the-shelf may refer to: * Commercial off-the-shelf, a phrase in computing and industrial supply terminology * Government off-the-shelf * Ready-to-wear * Shelf corporation, a type of company * Off the Shelf Festival, a festival of writing and ...
components are used, but where necessary for space or performance reasons, custom made components may be developed. Several instances of iterative design are as follows: *Wiki: A
wiki A wiki ( ) is an online hypertext publication collaboratively edited and managed by its own audience, using a web browser. A typical wiki contains multiple pages for the subjects or scope of the project, and could be either open to the pu ...
is a natural repository for iterative design. The 'Page History' facility allows tracking back to prior versions. Modifications are mostly incremental, and leave substantial parts of the text unchanged. *Common law: The principle of
legal precedent A precedent is a principle or rule established in a previous legal case that is either binding on or persuasive for a court or other tribunal when deciding subsequent cases with similar issues or facts. Common-law legal systems place great valu ...
builds on past experience. This makes law a form of iterative design where there should be a clear
audit trail An audit trail (also called audit log) is a security-relevant chronological record, set of records, and/or destination and source of records that provide documentary evidence of the sequence of activities that have affected at any time a specific ...
of the development of legal thought. *Evolution: There is a parallel between iterative and the theory of
natural Selection Natural selection is the differential survival and reproduction of individuals due to differences in phenotype. It is a key mechanism of evolution, the change in the heritable traits characteristic of a population over generations. Charle ...
. Both involve a trial and error process in which the most suitable design advances to the next generation, while less suitable designs perish by the wayside. Subsequent versions of a product should also get progressively better as its producers learn what works and what doesn't in a process of refinement and
continual improvement A continual improvement process, also often called a continuous improvement process (abbreviated as CIP or CI), is an ongoing effort to improve products, services, or processes. These efforts can seek "incremental" improvement over time or "breakth ...
.


Fast prototyping tools

One approach to iterative design is to use the highest level of abstraction for developing an early generation product. The principle here is that rapid development may not produce efficient code, but obtaining feedback is more important than technology optimization. Examples of this approach include use of non-functional code, object databases, or low code platforms - these allow quick testing of designs before issues of optimization are addressed.


Benefits

When properly applied, iterative design will ensure a product or process is the best solution possible. When applied early in the development stage, significant cost savings are possible. Other benefits to iterative design include: # Serious misunderstandings are made evident early in the lifecycle, when it's possible to react to them. # It enables and encourages user feedback, so as to elicit the system's real requirements. # Where the work is contracted, Iterative Design provides an incremental method for more effectively involving the client in the complexities that often surround the design process. # The development team is forced to focus on those issues that are most critical to the project, and team members are shielded from those issues that distract and divert them from the project's real risks. # Continual testing enables an objective assessment of the project's status. # Inconsistencies among requirements, designs, and implementations are detected early. # The workload of the team, especially the testing team, is spread out more evenly throughout the lifecycle. # This approach enables the team to leverage lessons learned, and therefore to continually improve the process. # Stakeholders in the project can be given concrete evidence of the project's status throughout the lifecycle.


Marshmallow Challenge

The Marshmallow Challenge is an instructive design challenge. It involves the task of constructing the highest possible free-standing structure with a marshmallow on top. The structure must be completed within 18 minutes using only 20 sticks of spaghetti, one yard of tape, and one yard of string. Observation and studies of participants show that kindergartners are regularly able to build higher structures, in comparison to groups of business school graduates. This is explained by the tendency for children to at once stick the marshmallow on top of a simple structure, test the prototype, and continue to improve upon it. Whereas, business school students tend to spend time vying for power, planning, and finally producing a structure to which the marshmallow is added. The challenge helps to build and develop prototyping, teamwork
leadership and innovation skills
and is a popular
STEM Stem or STEM may refer to: Plant structures * Plant stem, a plant's aboveground axis, made of vascular tissue, off which leaves and flowers hang * Stipe (botany), a stalk to support some other structure * Stipe (mycology), the stem of a mushro ...
activity. The challenge was invented by Peter Skillman of
Palm, Inc. Palm, Inc. was an American company that specialized in manufacturing personal digital assistants (PDAs) and various other electronics. They were the designer of the PalmPilot, the first PDA successfully marketed worldwide, as well as the Treo 60 ...
and popularized by Tom Wujec of
Autodesk Autodesk, Inc. is an American multinational software corporation that makes software products and services for the architecture, engineering, construction, manufacturing, media, education, and entertainment industries. Autodesk is headquartered ...
.


See also

*
Disruptive innovation In business theory, disruptive innovation is innovation that creates a new market and value network or enters at the bottom of an existing market and eventually displaces established market-leading firms, products, and alliances. The concept was ...
*
Extreme programming Extreme programming (XP) is a software development methodology intended to improve software quality and responsiveness to changing customer requirements. As a type of agile software development,"Human Centred Technology Workshop 2006 ", 2006, PD ...
*
Spiral model The spiral model is a risk-driven software development process model. Based on the unique risk patterns of a given project, the spiral model guides a team to adopt elements of one or more process models, such as incremental, waterfall, or evolut ...
*
Top-down and bottom-up design Top-down and bottom-up are both strategies of information processing and knowledge ordering, used in a variety of fields including software, humanistic and scientific theories (see systemics), and management and organization. In practice, they c ...
*
Paper prototyping In human–computer interaction, paper prototyping is a widely used method in the user-centered design process, a process that helps developers to create software that meets the user's expectations and needs—in this case, especially for designi ...
*
Scrum (software development) Scrum is a framework for project management with an initial emphasis on software development, although it has been used in other fields including research, sales, marketing and advanced technologies. It is designed for teams of ten or fewer me ...


References

* Boehm, Barry W. (May 1988) "A Spiral Model of Software Development and Enhancement," Computer, IEEE, pp. 61–72. * Gould, J.D. and Lewis, C. (1985). Designing for Usability: Key Principles and What Designers Think, Communications of the ACM, March, 28(3), 300–311. * Kruchten, Philippe. The Rational Unified Process—An Introduction, *


External links


Iterative User Interface Design at useit.com

Association for Computing MachineryClassroom images of Marshmallow Challenge
{{DEFAULTSORT:Iterative Design Design Systems engineering