Component Batch classification in process order

Dear,

I have one requirement w.r.t batch classification of components in process order. The batch classification field of components of process order contains some characteristics which have some values. The value field against these characteristics should not be editable in process order. It should remain editable only in BOM.

I suppose this can be controlled by authorisation, but I am unable to find the object which can control this.

Can anybody help me out.

Regards,

Prashant