Recalculate Work Order Cost

Hi to all

First of all, these questions are related to how to handle manufacturing errors, or reworks.

I want to know, if it is possible to:

1. Create a work order for an standard item

2. Prepare the Work order part list and route by running R31410 => This calculates the work order cost

3. Now edit part list and route (maybe adding or substracting materials and / or operations)

4. How I should do to tell the system to reclaculate the cost for this work order?

We are currently in 9.1

when we where on XE, R31410 could be run to not generate part list and route, but to update pert lista and route processing options set to blank and 3 respectively), and then the system used the current part list and route to update F3102 with the current part list and route cost