How should one think when it comes to parts and assemblies, where is the line between "this thing-a-majing should be one big Part" and "this thing-a-majing should be several separate parts merged in an Assembly"?
The actual scenario I'm in is that I'm going to make an advertisement-sign. Due to its size it will be manufactured in two phases; the "foot" (or whatever it's called), and the "sign" (where the screens are being put). The "sign" will also have a lot of small details, like 10x10cm big plates of steel to be put between the screens (to keep them in place).
For this project, I'm thinking like this:
Sign / holder - One part
The Foot - One part
The plates - One part (instantiated as many times as needed)
Assembly - Foot + sign + plates
I'm thinking in this way because the Sign is one big piece of solid metal, with no moving / loose parts in it. The foot is also one big piece of solid metal, with no moving parts in it (other than when merging it onto the sign). And the same for the plates, a lot of small pieces of metal that will be merged onto the sign.
Is this "correct" way of thinking about parts/assemblies in SolidWorks?
If not, how should for example the sign be split up into parts? Side plates, back plate, top plate, etc, and then merged into a stiff assembly?
I know this is by no means an exact science but I'm interested in how experienced CAD:ers are thinking when creating the projects.