Hi Jürgen，
Here is an example.
In a factory called 1000, it produces 1 PCS material A001, and needs to cost 3500 PCS raw meterial B001 and 1400 PCS raw material C001.
Besides, the rounding value of material B001 is 4000 PCS and material C001 is 2000 PCS, in other words, the minimum package value of B001 is 4000 PCS and C001 is 2000 PCS.
After running MRP, we need to make a PO in which material B001 needs 4000 PCS and C001 needs 2000 PCS because of the minimum package value.
After the production of materaial A, it costs the raw materials and leaves the B001 500 PCS and the C001 600 PCS, and then they become the idle materials easily.
Best Regards
Kevin Lai