Process modelling: XI-BPM and/or CAF?

Hi,

Looking at the functionality of CAF i'm a little bit puzzled. It seems CAF has its own proces-modeling-tool to create guided procedures where pre-defined actions are triggered in a proces-like way. The focus seems to be on human-machine workflow-interaction.

Besides this we have XI-BPM where proces-steps are modelled by using ARIS as modelling tool but where the focus is on machine-machine interaction (i.e. message-workflow)

1. How do ARIS-XI-BPM and CAF relate to each other from a modelling/BPM point of view?

What to do if I want to model business processes first, then see if available (enterprise) services expose the required functionality and if not, develop a composite application on top of them. Should I start first with ARIS, then go to SAP XI to invoke (enterprise) services and if this is not sufficient, UML-model again in CAF, invoke (enterprise) services again en create a composite application on top of them?

2. What to do if I want to use guided procedures in a purchase-process, which completely runs in SAP R/3. Do I have to use CAF, which is meant for creating composite application?

3. Can I expect that in the next release of Netweaver ARIS, CAF and XI-BPM are totally integrated so BPM can be developed in one platform ('BPP') and some functionality like guided procedure can be developed outside CAF?

Greetings Theo