Checkpoints and Transactions
A Checkpoint activity cannot be placed in or in parallel to a transaction. You can, however, specify that an implicit checkpoint should be taken as part of a transaction by checking the Include Checkpoint field on a transaction group.
For explicit Checkpoints, place the checkpoint activity outside of any transaction group. Also, make sure that if you have multiple paths in your process definition, the Checkpoint activity does not occur in parallel with a path that has a transaction group. Instead, any Checkpoint activities should be placed at points that are guaranteed to be reached before or after the transaction group is reached.
For more information about creating groups for transactions and including an implicit checkpoint in a transaction, see TIBCO ActiveMatrix BusinessWorks™ Process Design