Grey Physical Components

Hi All,

Can somebody explain to me the significance of the grey physical components in the PA (as opposed to the yellow physical components and blue behavioural components).

I have tried using them as major physical elements of the system but there is a clash between whether a yellow physical component is part of a physical breakdown or deployed onto a grey physical component.

If they are used as discrete systems of interest (for example you may want to have an airborne system and a ground system) how do you describe exchanges between them because I cannot see how to create physical links between grey components, only physical breakdown (ie contained in).