To update existing Work-In-Process in the system:
Go to File Maintenance.
Click on Tools > Manage Codes.
In the drop down choose Show codes for Rate Sets.
Highlight the Rate Set you want to update.
Choose Tools > Update Wip on Selected Rates.
Put in the date that you want the change to take effect (i.e., January 1, 2012).
Click OK.
This will update Work-In-Process entries with the new rates. This update process only updates those transactions originally entered using the same Rate Code.
