Canonical Device Supply Chain

Just to provide a framework for discussion, and because I’m that kinda guy, I’ll define a canonical device supply chain as follows…


The definitions of each of these elements are not strict, in fact they’re pretty squishy, but they do provide some landmarks that enable certain kinds of descriptions.


A material is any substance used in the creation of a part. This material may have been extracted from nature or recycled from another part. It is generally monolithic in some sense. Most importantly its purpose has not yet been established. It may be applied to many different parts in a variety of ways.


Parts are objects used in assemblies. Note that a special case of an assembly may consist of only one part. A part is an arrangement of materials that play a role within an assembly. An assembly may be a part, a subassembly, that is used in other assemblies. Mechanical parts tend to play roles based on their shape and material characteristics, electrical parts play roles based on their electromagnetic characteristics, informational parts play roles based on the information that they encapsulate and produce, etc.


Assemblies are collections of parts arranged to address a particular purpose. Assemblies may be arranged hierarchically as subassemblies fitted together into higher level assemblies. A special case of an assembly is a single part. Assemblies may be very abstract. For example, a phonebook in an information context is an assembly of phone numbers. Of course, in a mechanical context, a phonebook is an assembly of pages. The pages are parts of the phonebook assembly. Each page is an assembly of ink and paper. The ink and paper are parts of these assemblies. The ink and paper are manufactured from materials.


An installation is an instantiation of an assembly in a particular context in order to achieve some purpose associated with that context. The door to my room is an assembly instantiated specifically to my room in order to be able to close it off from the outside world. It could have been used elsewhere but happened to be used for my room. Note that there is no implication that context is necessarily geographically static. A diesel engine in a locomotive moves around, but the installation context is the locomotive.