Does anyone have an simple and effective framework to manage a portfolio?

This is a big question Rodrigo : )

Some things to consider.
- All PM's follow a standard practice
- Using a tool such as SharePoint with Project Online or Project Server, or Clarity, or some other PPM tool to allow each individual project to be managed under a 'single roof' for rollup reporting at the portfolio level
- Resource management to allow new projects to be slotted appropriately in accordance with resource capacity
- Use a visual to display to project roadmap, such as a kanban board approach. This will help to visualize where each project sits in the life cycle and allows for easier shifts in priority or resources
- Define KPI's and criteria for reporting
- Ensure all artifacts live in the chosen PPM tool, or an integrated document management system. Artifacts do not belong on individuals local machines.
- Enlist Knowledge Management best practices
- Define criteria and thresholds for how an item moves from production support, to an ad-hoc task, to an enhancement effort
...... there is plenty more. I'm sure others will chime in with excellent suggestions.