There wont be an exact formula for the perfect filter process. 50% will be guidelines, but 50% will remain a good feeling. With filtering and making decisions a voting process comes into the picture. There are different kinds of voting possibilities. Here 2 possibilities are described which are useful in a team to select ideas after the evaluation process:
 

• Cumulative voting: Every voter gets a certain amount of points and spreads them over the ideas
   
• Acceptance voting: Every voter can use a point/a vote for the idea he likes