Priority for source of supply determination

[Abrilsr_]

I want to know if possible to configure a rule for prioritizing the source of supply of a purchase requisition. 

1) I have 2 vendors which have source lists, info record but the system proposes both of them in the source of supply. We run MRP and the systema assignes one info record, what is the logic behind the selection?

2) I want when running MRP, there is one being selected over the other one without having to "fix" the vendor in the source list.. is this possible? if I enter a "1" in field MRP in source list, how would the system determine the source of supply then? 

Vendor 1 has 16 days delivery time, price for material is 187.68 EUR

Vendor 2 has 10 days planned delivery time and price 188.36 EUR

None of them have and agreement in place.

[Lakshmipathi]

System will give prioritize based on procurement priority and costs incurred for procurement