MRP not considering Quota Rating

Hi

I have material produced in house and maintained quota for all production versions.I had quota allocated qty,base qty.

ex: PVersion A: quota-10: all qty: 1400: quota base qty: 2000

PVersion B: quota-20: all qty: 800: quota base qty: 0

PVersion C: quota-70: all qty: 2800: quota base qty: 100

I had PIR for 1000 qty.System is not splitting as per quota rating.It is only splitting as per quota rating.The split is happening as percentage and planned orders as 100 for A, 200 for B and 700 for C. I feel the system shud have allocated to B since it has the lowest quota rating.(quota rating for above data shall be 340 for A , 40 for B, 41.3 for c).Any body can evaluate?