An ASSEMBLY is a number of parts or subassemblies, or any combination thereof, joined together
to perform a specific function. Figure 1-5 shows a unit (2) with its six assemblies. The assembly (A6)
contains six subassemblies.
Figure 1-5.Unit and assembly.
A SUBASSEMBLY consists of two or more parts that form a portion of an assembly or a unit. It is
replaceable as a whole, but some of its parts are individually replaceable.
The distinction between an assembly and a subassembly is not always exact; an assembly in one
application may be a subassembly in another when it forms a portion of an assembly. Figure 1-6 shows a
printed circuit board subassembly and some of the parts which may be mounted on it.