Not in a marketing sense, but strategically, to yourself, your partners, your coaches, your investors:
What is it for? When someone hires your product or service, what are they hiring it to do?
Who (or what) are you trying to change by doing this work? From what to what?
How will you know if it's working?
What does it remind me of? Are there parallels, similar projects, things like this that have come before?
What's the difficult part?
How much of your time and focus are you spending on the difficult part?
What part that isn't under your control has to happen for this to work?
How much (time and money) is it going to take to find out if you've got a shot at this working out?
What assets do you already own that you'll be able to leverage?
What assets do you need to acquire?
What do you need to learn?
After the project launches, what new assets will you now own?
Is it worth it?
From which people will you need help? Do they have a track record of helping people like you?