Requirements of Selection Systems

The examples on these pages are mainly concerned with selection of materials for engineering applications. However the principles are general, and can be applied to a diverse range of selection problems, for example selection of standard components (eg fasteners, bearings, actuator, couplings, resistors, capacitors, batteries...); structural members (eg I-sections, tubes, rolled-hollow sections...); or even manufacturing processes (eg casting, welding, forging, injection moulding...).

Selection of standard "entities" in engineering invariably has two main steps, as illustrated below. In these pages, these steps are called the "screening" step (examples of which may be found on the case studies pages) and the "supporting information" step. The data requirements and selection/searching strategies in the two steps are completely different. Although these pages are mainly concerned with computerised selection systems, the screening and supporting information steps are characteristic of all engineering selection activities even if they are performed on paper using handbooks or manufacturers catalogues.

 

Figure 1 Structure for selection of "standard" engineering entities

Databases of engineering materials and standard components have been widely available for some time. Developments in information engineering, particularly CD-ROM technology and the Internet are rapidly expanding the availability of large quantities of additional information about these entities. However, it is only through use of a structured approach to information engineering that these diverse resources can be exploited fully and "optimal" selection of materials and standard components can be achieved.