It should be noted that a score and a cost is not always sufficient to derive a unique ranking. Whilst an option with a higher score and a lower cost should always be ranked higher than another option with a lower score and a higher cost there are often cases where the comparison is less straightforward. For example an option with a higher score may cost more than an option with a lower score. In this case it is necessary to apply judgement as to the relative importance of the cost difference against the difference in score. It is best practice for such judgements to be made by those who bear the ultimate responsibility for the decision taken.
The initial weighting attached to cost as against the scored elements of the evaluation may be of assistance in making this judgement. However there is no way of devising an evaluation methodology that totally eliminates the need for a judgement to be made regarding the trade off between cost and other criteria. Projects teams should therefore be mindful of the need to ensure such decisions are taken by the appropriate body and that body has sufficient information to take that decision.