Seems to me that breaking down an assembly is a manufacturing operation,
with the assembly being raw material.
An assembly is certainly the input/raw material to the process.
I wouldn't call it manufacturing though, but perhaps a 'breakdown process' (the counterpart of an 'assembly process'), which might be part of a manufacturing, or a junkyard/recycling/other - eg retail - (business) operation.
Eg retail businesses: raw material = stock + container
container = crate / pallet / etc
The container can have real value, and is tracked and accounted for.
Also you can have containers within containers, although the system might not need to know this, just allow multiple types of containers (parts) plus multiple types of raw material (parts or assemblies) in an incoming package (assembly)