Important projects in the portfolio backlog need to be delivered. Budget estimates are needed to prioritize the projects. How should the project budgets be estimated?

In an agile context, especially for portfolio prioritization, breaking projects into features allows for more granular estimation. Combining this with feature value (to understand impact) and team velocity (to estimate effort/time) provides a robust basis for budget estimation, enabling prioritization based on cost-benefit analysis, aligning with lean and agile principles.

While experience is valuable, relying solely on the sponsor, product owner, and team's *experience* without a structured estimation method like decomposition into features and velocity can lead to less accurate and less defensible budget estimates.

The team facilitator primarily guides processes; while historical data is useful, the facilitator isn't typically the sole person responsible for *arriving* at budget estimates without team input and detailed breakdown.

While the product owner obtains details and considers team experience/velocity, the critical element missing is the decomposition into features which is fundamental for effective agile estimation and prioritization at a portfolio level.