Converting workflows for old carts

Hi,

We are upgradig from SRM 5 to SRM 7.1 and implemented PCW for carts.

Question-->After upgrading ,we need to convert all old carts(which are waiting approval) to new workflows so we need to run the report to u[grade workflows via SPRO.

HOwever after doing so,we obserevd that all carts which are in SAVED status also get converted and then we see workitems for these SAVED carts also in respectove approvers inbox.

Can anyone explain me the exact steps for converting old workflows to new workflows after system upgrade?