Product Master - APO

Hi ,

Work-scheduling View of Material master is having field called " Prodn Controller " which can be seen at APO Product master level in product master overview tab as Prodn planner above SNP planner . Work Scheduling View in SAP R/3 is maintained generally if Materila is In - House manufactured ( type E) now when we CIF Material with External procurement is this field mandatory to maintain for Externally procured materials too ? If not how this settign can be done to aviod to maintain work scheduling view in R/3 for Externally procured material still CIF materila master to APO as product master ?

Thanking You

Ratnakar Pawar.