Steam Locomotive Terminals Operations

[tompm]

I am currently very frustrated with trying to design and layout the engine terminal on the new layout. I have a bunch of structures with their appropriate uses. It is where and how to arrange them that is driving me nuts.
 
After some contemplation I realize that perhaps my understanding of how things work may not be the correct way or the best way. Thusly here is my question:
 
When a steam locomotive comes into a terminal for servicing is there a set way of doing things? By such I mean does he dump his ash first, then get water, then coal, and lastly sand if needed? Or is there some other method to the madness?
 
I believe once I have a better understanding of how this works I can complete the terminal and yard.