Standards for product modeling.

The models include :

(a)  A presentation model which defines the type of presentation of information. For instance how the product can be visualized on a CRT or paper. Features like colour, illumination, text font, view angles and so on are determined here,

(b)  Materials model: is where the characteristics of material can be described. For instance an elasticity matrix, material-specific coefficients such as a coefficient of expansion, thermal conductivity, heat transfer are specified.

(c)  Tolerance model describes dimensional tolerances, geometric tolerances, from tolerances and so on.

(d)  Surface model describes the specification for surface finish required.

(e)  Form-feature model describes the object from the point of view of manufacturability whereby the form pattern is described or a method to produce the form element. The manufacturing relevant features can include holes, threads, keywords and so on.