'''Function''' The function of a commodity is the action or actions it is designed to perform. For software, the function means the action or actions the software performs directly related to a defense article or as a standalone application.
=== By Clickfold Plastics, Inc. ===
'''Fit''' refers to the ability of the part or feature to connect to, mate with, or join to another feature or part within an assembly. The “fit” allows the part to meet the required assembly tolerances to be useful.
'''Form''' refers to such characteristics as external dimensions, weight, size, and visual appearance of a part or assembly. This is the element of F3 that is most affected by an engineer's aesthetic choices, including enclosure, chassis, and control panel, that become the outward "face" of the product.
'''Function''' is a criterion that is met when the part performs its stated purpose effectively and reliably. In an electronics product, for example, function can depend on the solid-state components used, the software or firmware, and quite often on the features of the electronics enclosure selected. Poorly placed or sized ports and misleading or missing labeling are two of the most common ways in which an enclosure can fail the function criterion.
