4 Conceptual design

4.1 Establishing the design space

We might also come across this process of defining the design space in other fields such as laying out a page on a word processor, designing our garden, or planning to redecorate a room. This is not really designing in the sense of the plastic kettle I discussed in Section 2. There is a difference in complexity between the designing we do in our daily lives and the activities undertaken by professional designers. This section takes a closer look at this complexity and begins to unravel the design activities which are crudely represented in the models of design discussed in Section 3.

There are experts in all of the various different design fields, and for many people designing is their profession and their livelihood. These experts will be people who

• have specialist knowledge;
• are likely to be familiar with the types of problems which can arise in that area;
• have a competence with making and using the types of models used in that field;
• may have a wide range of contacts to assist their work.

When your own designing becomes too complicated you might have found yourself calling in an expert: for example, using an architect to help you achieve a new extension to your house. He or she may be able to assist you with the concept designs or to identify the function restrictions encapsulated in the building regulations.

In the concept or conceptual stage of design, the emphasis for the designer or design team is on defining the appropriate solution space which best matches the known problem space. Of course, as we have seen, achieving this is not easy for a number of reasons. Firstly the problem may not be well defined. Secondly the act of generating solutions can allow us to reconfigure the problem. A spiral of development is created where defining a new boundary to the problem space facilitates even more new ideas in the solution space which further tests the problem space.

In order to find the appropriate design space, designers usually have to go through iterations of generating ideas and testing them against the known problem. This may result in changes to the formal statement of the requirement (the product design specification) and/or changes to the proposal. At the concept stage there can be huge variations in the specification and in the types of proposal offered but the objective will always be to do two things. Firstly at the concept stage designers seek to improve the specification so that it more accurately represents what is actually required. Secondly designers seek to offer a range of ideas which meet, as well as possible, the developing design specification. So concept designing has the tricky function of offering creative interpretations to an emerging problem. To help with this dual activity, designers use a wide range of modelling skills in addition to their knowledge and experience.

I shall develop my discussion of conceptual design, and particularly this notion of solution space, using two examples: the design of the hull of a sailing boat and the development of human-powered flight.