To understand the current evaluation system I feel we need more information.
Eg what is the factor for the 3rd ranked supplier? (1st - 1, 2nd - 0.5, so third can be in geometric progression ie 0.25 or else). Likewise down to the n-th ranked supplier.
furthermore, if you could give an example of 1-3 suppliers ranking under the current and desired system, it would be easier to see what mathematical equation/model this would fit it.to develop a formula that converts the combination of a fixed price/quality split (as with the old process) and a supplier’s quality score (out of 100% as with the new system) into a factor to input into the new system.