Basic design cycle
From WikID
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This article is part of the Bachelor design guide; the original version can be found at page 30. |
In design, reasoning takes place from goal (the function) to means (the form). In designing many means can realize the goal and it is initially uncertain what form is (the most) effective. It therefore needs no further explanation that design is in essence a trial-and-error process that consists of a sequence of empirical cycles. In these cycles the knowledge of the problem and of the solution(s) increases spirally. Roozenburg and Eekels call the model of this cycle the basic design cycle. According to Roozenburg and Eekels, the basic design cycle is the most fundamental model of designing[1]. Someone who claims to have solved a design problem has gone through this cycle at least once.
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Analysis
The point of departure in product design is always the function of the new product: the intended behaviour in the widest sense of the word. Not only the technical function, but also the psychological, social, economic and cultural functions that a product should fulfil. In the analysis phase the designer forms an idea of the problems around such a new product idea (the problem statement) and formulates the criteria that the solution should meet (the design specification). Essential to any problem definition is a goal: in defining a problem, one will have to form an image of a future situation, which is to be prefered to the present one.
Synthesis
The second step in the basic design cycle is the generation of a provisional design proposal. The word synthesis means the combining of separate things, ideas, etc., into a complete whole. Synthesis is the least tangible of all phases of the cycle, because human creativity plays the most important part. But the origination of ideas cannot be localized in a particular phase of the basic design cycle: the synthesis step is only the moment of externalization and description of an idea, in whatever form (verbally, sketch, drawing, model, etc.)The result of the synthesis phase is called a provisional design; it is not yet more than a possibility, the value of which can only become apparent in the later phases of the cycle.
Simulation
Simulation is a deductive sub-process. Simulation is forming an image of the behaviour and properties of the designed product by reasoning and/or testing models. Here, the whole array of technological and behavioural scientific theories, formulae, tables and experimental research methods is available to the designer. Yet, in practice many simulations are based merely on generalizations from experience. Simulation leads to expectations about the actual properties of the new product, in the form of conditional predictions.
Evaluation
Evaluation is establishing the value or quality of the provisional design. To do so, the expected properties are compared with the desired properties in the design specification. As there will always be differences between the two, it will have to be judged whether those differences are acceptable or not. Making such a value judgement is difficult, for usually many properties are involved.
Decision
Then follows the decision: continue (elaborate the design proposal or manufacture it) or try again (generate a better design proposal). Usually the first provisional design will not be a bull’s eye and the designer will have to return to the synthesis step, to do better in a second, third or tenth iteration. But one can also go back to the formulation of the problem and the design specification. Exploring solutions appears to be a forceful aid to gaining insight into the true nature of a problem: one might therefore often want to adjust, expand, or perhaps sharpen up the initial formulation of the problem. The design and the design specification are thus further developed in successive cycles and in a strong interaction, until they fit one another.
