Check Mode Determination in APO

The check mode derived from the product master record and the business event determines the type and scope of the checks to be carried out. In addition, the check mode controls consumption using the forecast.
The SD (R/3) uses the requirements class of the requirement as check mode. As of R/3 Plugin 2000.1, the requirements class (via the strategy group in the material master) is transferred to the location-specific APO product master (tab page ATP). No plausibility check takes place.
Therefore, you should not enter any other check mode in the product master as the check mode in the product master must correspond to the requirements class from the R/3 System
(1) Through the MRP group or strategy group in the MRP view of the material's master record
(2) Through the item category and the MRP type in the MRP view
The item category is derived from the item category group in the Sales view of the material master record and from the order type of the sales document. Together with the MRP type in the MRP view of the material master record, the item category determines what requirements type is selected. The advantage of this method is that the selection of the requirements type depends on the business process (such as quotation, sales order, or repair).