This one’s an interesting question since there really is no hard and fast rule and it’s all down to choice. But does aesthetics come into play here, is it more natural to read and scroll through a process one way than the other ? If we take the humble desktop mouse as an example, the scroll wheel will allow us to examine a process modelled up and down quite easily on screen, yet print it off for a workshop and you’ve got a bit of a problem for continuity purposes.
So how do you map yours and why ?
(and we’re talking about the relatively structured processes that can be mapped and presented to the business users through portals, not the haywire dynamic ones)
And a final thought: could you ever see yourself mapping in 3D ?