Appropriate
This idea is is something that is needed, builds on what the family is capable of and has resources for, and is within the realm of areas the family is or might be engaged.

Challenge
The idea is not something that has been done before, pushes the boundaries of possibility for the family, and maybe entails a moderate amount or risk. Therefore it is a good idea but not guaranteed of success.

Opportunity
The idea should be timely, and have a timeline for structure.

Competence
This has to do with the proposer: what are your own qualifications and abilities that you can use to make this idea successful?
What do you know and what do you need to learn to develop the idea?

Engagement with Others

Who else in the family and around you are allies, supporters, partners who offer skills and capabilities that might help you develop the idea? Are they on board?

Homework
Have you studied how this idea has been done elsewhere, or what others have done in this area? Is your idea grounded in reality, and have you done your homework in looking at the existing learning about this idea?
Are you trying to do something that others have done better, or reinventing something that is already there? What makes your idea unique? How is your idea contributive and something that people need/want?