From the analysis of an initiative, the portfolio can take a decision if the initiative shall be made or not, which depends on how the initiative fit to the overall organizational purpose and the current strategy and tactics.
Since there are many parameters to consider, like platform or not, lead time, cost, quality, short-term or long-term, the need of being fast to market, etc., the decision can sometimes be cumbersome to take. But, with a way of working that also considers the wholeness of the current architecture and how the initiative will fit-in to that, the decision will be more realistic and therefore also long-term correct.
From the prioritized backlog it is easy to make the overall road map, which takes the difficulties with long-term predictability into account.
For more information about the actual management of going from unprioritized initiatives to prioritized ones, please see this article.