mps and mrp

dear expert;

i understand that when i run MPS (md40 or md42 ) just mps item will be planned , but when i see the stock req list (md04) , in the order report for my mps item i saw planned orders for all mrp material ( my bom are 2 levels) so i dont understand . can u explain?

this mps run was after many mrp run before when my mps item was mrp item ( before i change its mrp type ).

can u explain why ?

thank u in advance