We built in task steps for renewal, amendment and termination. No steps for administrative. We've got 2 templates - one for new contracts and one for legacy contracts. Both have the amendment options and tasks built in. The trick is to think through your current types of amendment procedures and map them to the 4 options in the system.
But there is one MAJOR restriction in Ariba. if you build in the various amendment tasks to trigger when you select those amendment types they only come up once to be completed - what this means is if you have a multi year contract with numerous amendments, after the first set of amendment tasks are completed, then the contract owner has to manually create the tasks for any subsequent amendments. Ariba really need to look at the whole amendment process because it doesn't match real world situations of how buyers have to work with contracts. Happy to show you a demo of what we set up. In exchange, I'd be interested to know if you are using the DFS enablement and negotation function with main agreement and clauses. We couldnt' get it to work so we've dropped it and just pass word documents back and forth.