用户可以使用定义系统消息来控制采购申请转变为采购订单时订单数量不超过超过采购申请的数量，具体做法：手工添加应用区域06 消息号码为076的消息改成E-错误信息. 

路径：SPRO->物料管理->采购->环境数据->定义系统消息的属性 

定义系统消息的属性



In Purchasing, certain system messages containing important information for users may be issued from time to time (for example, "Net price of purchase order is higher than material price"). Users can act on the information thus provided.

In this step, you can specify whether the sap System:

•Suppresses the relevant information•Issues it as a warning message•Issues it as an error messageIn the case of an error message, processing cannot be continued until user input has been corrected. You can also group the messages according to user classes by saving the messages as different versions.