Portfolio Managers use the Stage-Gate process for managing Project Portfolios.
In the Stage-Gate process, each phase (stage) is divided by a decision point (gate).
It can be applied across the entire project life cycle. It is important to define conditions for passing through a gate.
In fact, at each gate a cross-functional team evaluates the project status against the pass/no-pass conditions.
So, active projects within the portfolio are subject to the Stage-Gate control process. Each gate will have a set of metrics by which projects will be evaluated.
Keep in mind: Portfolio Managers review each project at each gate before making a go/no-go recommendation to the governance council.