MPS items planning in Manufacturing Plan

Hi Experts,

We use Manufacturing plan of ECC type where custom hooks used to convert item planning method from MRP to MPS for ODS data before

launching the plan. Also these MRP planned items are only lower level items i.e components and need not to be MPS.

Does anyone knows for what purpose/scenario this conversion may be required.

The only answer so far I heard is that plan may not show proper pegging information in the ATP inquiry screen if they aren't MPS planned but

am not fully convinced and require expert advice.

Thanks in advance,

Abhishek Sharma