Agreed assessment criteria are useful for taking into account the concerns of multiple stakeholders and selecting ideas.
Brainstorm, refine and agree a set of assessment criteria. These need to be structured so that they encourage individual participants to consider the perspectives of other stakeholders when making their assessments.
For example, if you were selecting a product design to take forward into production you might give each of the ideas a score of 1-5 on the criteria of: technical feasibility (the concern of stakeholders in engineering), cost (the concern of finance), passion for the idea (the concern of the project team), portability and size (which might be some of the concerns of the customers).
Score all your ideas against individual criteria before totalling the final score for each idea.