Design may be described in a variety of ways
and degrees of complexity. Some design cycle
models are simple and some are more complex.
The design process usually consists of successive
stages that can be arranged as a systematic cyclical
process that eventually converges to produce a
solution to a problem.
The DCM comprises six stages, as follows:
• identifying or clarifying a need or opportunity
• analysing, researching and specifying requirements
• generating ideas and solutions
• developing the chosen solution
• realizing the chosen solution
• testing and evaluating the chosen solution.
The design brief is the formal starting point for a new design. It is a statement of the expectations of the design. The brief does not provide the design solution, but is a statement that sets out:
• the design goal (for example, a working prototype to be evaluated in terms of its feasibility for volume production)
• the target market for the product (for example, for children, disabled adults)
• the major constraints (for example, should comply with new legislation, have fewer working parts, be cheaper to manufacture) within which it must be achieved
• the criteria by which a good design proposal may be achieved (for example, increased value for money and/or cost-effectiveness for manufacturer).
The context of the problem is described and a concise brief stated. The design process can begin with a problem, an identified need, a market opportunity, a demand, a desire to add value to an existing product, or a response to opportunities presented by technological developments.
The initial design problem is a loose collection of constraints, requirements and possibilities. From this, the designer has to make a coherent pattern.
The design brief states the intended outcome and the major constraints within which it must be achieved.
The design specification justifies the precise requirements of a design. The specification will include a full list of the criteria against which the specification can be evaluated.
Developing the specification from the brief is an evolving process beginning with an initial set of specifications and culminating in a final product design specification (PDS).
Divergent thinking is used to consider ways in which a problem may be solved. The starting point for the generation of ideas should be the design specification, and proposals should be evaluated against this specification, with evidence of relevant research used to rate the ideas in terms of their usefulness. A variety of approaches should be used, and different possibilities explored and analysed, before deciding on the most suitable solution.
A final concept is developed taking into account the conflicting needs of the manufacturer and the user, and the requirement of the design as set out in the specifications. A complete proposal is developed based upon the research and the designer’s personal ideas. This stage involves detailed drawings (of a style relevant to the task).
The final outcome is tested and evaluated against the requirements set out in the specification. Recommendations for modifications to the design are made. A reiteration process should now begin.
The model emphasizes that designing is not a linear process. Evaluation, for example, will take place at various stages of the process, not just at the end. Similarly, ideas for possible solutions are not only generated at the “generating ideas” stage; some good ideas may develop even as early as the “identifying needs” stage. In practice, it is impossible to separate the stages of the design process as clearly as the model suggests.
The designer’s role varies depending on the complexity of the process and the intended outcome.
Designers often work as members of a team. Priorities will vary depending on the nature of the activity. For example, the information required by an architect will be different from that required by an engineer.
Depending upon the nature of the problem, not all elements of the cycle carry the same weight in terms of time allocation and complexity. Points to consider include cost, resources, skills, time, original design specification and product modification.
Convergent thinking is analytical and solutionfocused, for example, during evaluation. Divergent thinking is conceptual and problem-focused, for example, used to generate ideas.
For example, the use of a new material for a product may be a radical leap forwards but the product may look very similar to previous products: a tennis racquet made from carbon fibre is a radical development, but the shape and form are similar to previous designs.