The use of a design process

A design process is an organised way of designing and making a product. Product development is usually cyclic or iterative rather than linear, because ongoing research, modelling, testing and evaluation can cause designers to return to earlier stages and modify the proposal.

A typical process moves through problem/brief → investigation → specification → idea generation and development → modelling → planning production → prototype manufacture → testing and evaluation, with feedback between the stages.

Design brief

A design brief outlines the problem and the needs or wants of a specific user or target market without prescribing the final solution. It can include:

a description of the problem, need or situation
the context in which the product will be used
inadequacies or limitations of existing products
information about the client or user group
the product’s basic purpose and key functions
important areas that will affect the success of the product.

Investigation, research and analysis

Research should provide information that can influence the design rather than simply filling pages. Primary research can include using existing products, assessing their function, components, materials and manufacture, comparing products, focus groups, questionnaires and practical material testing.

Designers may also:

discuss requirements directly with clients or user groups
consult specialists such as engineers, material specialists or electronic-product developers
investigate historical and current styles, fashions and trends
analyse anthropometric data to ensure appropriate fit
investigate relevant standards, safety requirements and material or component information
consider social, moral, cultural and environmental factors
identify constraints such as size, environment, cost and method of use.

Secondary research can provide information about materials, components, construction methods, designers and design movements, manufacturing methods and published anthropometric data.

Inspiration material

Designers can organise visual research using mood boards containing relevant images, colours and styles. Inspiration boards can contain material samples, finishes, products, colour samples and other physical or visual references. These should help direct idea generation rather than determine one solution too early.

Design specification

The specification is produced after investigation and analysis. It records the essential requirements and desirable features that the product should meet.

Typical areas include function, user, environment, sustainability, maintenance, size, weight, ergonomics, aesthetics, cost, quality and safety. Criteria should be specific enough to guide development and later evaluation. The specification should be referred to throughout the process rather than used only as a final checklist.

Idea generation

Designers can generate and develop ideas using several methods:

mind maps to organise related elements and encourage connections
SCAMPER — Substitute, Combine, Adapt, Modify, Put to another use, Eliminate and Reverse
collaborative discussion with specialists, clients or members of the target market
sketching and modelling ideas, then modifying them in response to feedback
techniques such as the 4×4 design activity, where another person develops an initial idea to introduce alternative viewpoints
Edward de Bono’s Thinking Hats, which encourages a group to consider an idea from different viewpoints.

Modelling

Models allow ideas to be developed and tested before committing to manufacture. Quick sketch models can be made from easily worked materials such as card, paper, foam, clay or wire. Scale models communicate form and proportion, while full-size models are useful for testing size, ergonomics and function.

Photographs and records of models should capture what was learned. Sketching over photographs can be used to show proposed modifications for the next iteration.

Planning manufacture

Careful planning helps make production efficient and repeatable. Designers can use spreadsheets, flow charts and other planning methods to record materials, costs, operations and timings. In commercial manufacture, planning may consider concurrent stages, sub-assemblies, sequence of operations and quality-control checks.

Manufacture, testing and evaluation

Manufacture should follow the planned drawings, material information and production sequence. Testing and evaluation are ongoing parts of the design process and can include:

evaluating findings from product analysis and research
reviewing initial designs with clients or potential users
evaluating CAD views before physical manufacture
testing models and prototypes with potential users
carrying out material and manufacturing trials
comparing the completed prototype with each relevant specification criterion
testing function, ergonomics, aesthetics and other requirements in the intended environment
obtaining independent feedback or specialist opinion
identifying justified modifications for further development.

The strongest design decisions are based on evidence gathered throughout the process, not only on the designer’s personal preference.