MRP4 filed individual/collective is 1 when planned order type is LA

hi guys :

I find that planned orde type is LA but it generate purchase requirment when componet MRP4 individual filed is 1.

I am try to use indepent requirment,it is not crete purchase requirment,base on my konwlege,if mrp4 individual field of material is 1,the material generate purchase requirment when crete sales order . I don't konw what reason this problem.