it's a bit complicated, for the approval, you need to have a "waiting approval" status for the object (asset/equipment) which should exist with or without the workflow so the users can't use it until it's approved (a user status/block or something similar).
in this case you have a few options:
- A decision task - simply approve/reject the asset/equipment by finance. reject-> return to the creator to edit.
- You can create a small screen where the finance can select the cost center (update it using a FM)
- A synchronous tasks which sends the finance to the standard transaction and ends only after they change the cost center (raising the terminating event by change documents for example)
Sending data form the creation of an asset to the equipment sound like something that should be done by user exit or BADI if no approval is needed, if this is a part of the approval process - you can use a background task (this is the same as calling a FM).
