This page is part of the Agency Evolution framework.
Now you have a big list of prioritised mission-ready ideas, and a clear picture of the constraints, it's time for the really difficult job of selecting which missions to launch next.
In an ideal world, work one cycle ahead with this selection, so the mission teams have time to get prepared and do some thinking before their formal launch. A lot of agency founders recoil at this — "but we want to have an idea and get it done immediately!" That sort of urgency is rarely necessary, however much agency culture pushes the need for speed. Again, the mantra is 'slow down to go faster'. It's counter-intuitive, but it works.
If you really want to, you could keep one of your quarterly slots for last-minute ideas, and plan the others (if your agency size and stage allows you to have more than any one slot in a mission cycle.)
How you do the selection depends on what works for the culture of your agency. Here are some ideas: