Table field type change (need a faster process)

In the process of changing table field type

1) copy all data out from system

2) delete data in the table

3) change field type

4) upload data back to the table , Finished.

It is very fast,

but in the case of changing characteristic attribute in batch(022) classification, it is very slow. I have to

1) Copy all characteristic value of batch and material (by creating customized program)

2) Download assigning material and assigning batch (by creating customized program)

3) Delete class in all material and batch (by using SAP standard program)

4) Delete class (by using SAP transaction)

5) Change characteristic attribute (by using SAP transaction)

6) Recreate class with same characteristic (by using SAP transaction)

7) Assign class to material (by using CATT)

8) Assign class to batch (by using CATT (Very slow))

9) Upload characteristic value back to material and batch (by creating customized program).

Does anyone ever change characteristic attribute in go-lived system? Do you use the same process as me? If not please suggest the better process or any techniques that can faster the work?

Best Regards,

Chaiphon (To)