安裝與升級 > Upgrade Guide﹝升級指南﹞ > The Windchill Upgrade Procedure > Stage the Source Data for the Upgrade > Retaining New and Checked Out CAD-Files Work
  
Retaining New and Checked Out CAD-Files Work
Before upgrading, all CAD tool users must upload Creo local cache changes or CAD tool Workgroup Manager local cache changes on the client side to Windchill individually if these changes need to be preserved during the upgrade. After upgrade, the user need to clean the local cache and start with a new local cache.
The user does not need to check in objects to Windchill. If the user wants to save the work during upgrade, they need to save it to Windchill (upload) before the upgrade. After upgrade, the user has to start with new local cache as the server user starts interacting differently. The local cache is tied to a particular Windchill server. If the server is changed, the local cache needs to be discarded.