During the idea generation stage of the new product development process, it is important that

While all ideas that come from brainstorming are good, it is very important that in the idea generation stage, some ideas must already be screened out. For this purpose, it is very important that the ideas by screened and tested for viability meaning that they can be done and backed by facts. 

the only think I don't know how to do is math

Explanation:

97% of my questions are math related