5. Sources and databases. Selection software

The nature and precision of the data required in the design procedure and in the various stages of material selection vary considerably according to the degree of advancement in the procedure. At each stage, therefore, the most convenient source of information for the required precision needs to be selected. Traditionally, these sources of information have been books, catalogs and supplier data sheets. Increasingly, these data now exist in the form of computerized databases, available on diskette or online. Finally, recent years have seen the development of systems that are no longer simply data banks, but genuine computerized aids to the selection of materials and processes.