You have selected the special procurement key "Subcontracting" in the material master for the finished product or assembly that is to be produced by the subcontractor.

If a requirement exists for a finished, the planning run generates a purchase requisition with item category "L" (subcontracting) or a planned order with special procurement "L". This planned order is converted into a purchase requisition with item category "L". You can see the item category or the special procurement "L" when you display the MRP element in the stock/requirements list or in the MRP list.

At the same time, the BOM is exploded for the finished product or the assembly during the planning run. Dependent requirements are created at finished product level for the components at the start date of the planned order or for the release date of the purchase requisition. These dependent requirements are included in the planning run as special dependent requirements. However, if you want to make changes to quantities or dates, you can do so in the same way as for normal dependent requirements.