I would typically use something like this. Note that this is for 6.x, I'd be changing details for 7.
thanks for reply.
What about my diagram if we want to keep the things very simple and not to go in deep detail?
That's hard to evaluate when I don't know the level of detail you want to go into
Take a look at the diagram I posted and strip out the pieces that are too deep. Then compare that to what you have.