When a production order is changed, the MRP controller who is responsible for the production order can be informed by using SAP Business Workflow. The MRP controller receives a work item and can maintain the production order from there. You program which changes the MRP controller is to be informed about in the function module exit EXIT_SAPLCOBT_001 (customer enhancement PPCO0001).
For more information, for example, about how to inform the production scheduler instead of the MRP controller, refer to the component BC - Basis by choosing Business Management -> SAP Business Workflow -> Reference Documentation -> Workflow Scenarios in Applications -> Production Planning and Control -> Production Order Changes (PP-SFC).