ABSTRACT
Achieving a functional product is central to the design process, and therefore using feature based design the designer creates the product using a range of functional features. The definition of a universal set of functional features is unlikely. Each product has its own set of objectives that can be translated into functional requirements, as shown by the example in Figure 1. This gives each product its own set of relationships between form and function. Different forms may achieve the same function in the context of different product types and the same forms may achieve different functions. Some forms may have multiple functions. The set of form/function relationships for one product type has no obvious relationship with that for another product type. This problem provides too large a number of permutations to define a universal set of functional feature types. The functional meaning of specific form features is also changed by its use on a particular product range, as illustrated in Figure 2. For example a hollow boss geometry may be a flange, a rib or a base feature on a ‘pot’ type product (Figure 2), but can only be a boss type feature on the ‘angle bracket’ type product shown in Figure 1. Therefore the geometry has to be captured within the product range (functionality) context.
