Field help (QUAFLG) 

This code is used to define whether this product must be controlled on receipt into stock.
The assigned product Category determines the initial control value for the product-site record and the supplier-stock record. The supplier-stock record value provides the default value for purchase orders.

When the quality control code associated with the product or with the product-supplier combination has the Non-changeable control value, the field that corresponds to the order line cannot be accessed in entry mode, irrespective of the transactions setup.

This information will then be used at the receipt and cross-checked with the management rule defined for the product category and associated with the movement type Supplier receipt to determine the product status and to generate, if necessary, an analysis request.