Check points for a new game mechanic design

From my game development experience, I found that there always had problems while making a new game mechanic design.

Here are the main problems: 
  • The mechanic doesn't drive player attention;
  • The mechanic doesn't help user retention, drive income, and make surprise;
  • The programmer and artists cannot figure out what to do based on the design;
  • Cannot work out the UI/UX based on the design;

So check points for different parties:

Producer and Operations:
  • Is the mechanic worth to work out? (..  ROI) 
  • Can user retention be improved?
  • Can it drive income and How much will be?
  • Can the new mechanic cohere the main gameplay?

UI & UX:
  • Can work out the game flow based on the design?
  • How the new mechanics associate with other UIs?
  • When will user learn it and How can to learn?

  • Can the design tell the assets need to produced based?
  • Can the assets production meet the deadline?

  • Can work out data design based on the game mechanic?
  • Can work out program flow based on the game mechanic?
  • Is the mechanic contradict itself?
  • Is the mechanic too complex so that it is gold plating (over-polish)?
  • Can the implementation and testing meet the deadline?