Preparing to Run Transaction SPDD 
During the adjustment of ABAP Dictionary objects, the ABAP Workbench already has the new release (however, not the applications).
Before you begin adjustment, set the system change option for the SAP System to "modifiable" for all namespaces:

When you make adjustments keep the following in mind:
You should use the same request for all further changes you make in connection with SPDD.
For the adjustment of future Release upgrades or other SAP Systems (such as production systems), it is important to observe the following. Create exactly one request in the Workbench Organizer for all corrections carried out in connection with transaction SPDD. For further information read the sections Adjusting Other SAP Systems and Handling Change Requests During Adjustment.