Computerworld Article — Project Portfolio Management
As its name implies, project portfolio management groups projects so they can be managed as a portfolio, much as an investor would manage his stocks, bonds and mutual funds.

Focused Performance Article — Project Portfolio Management: The First Cut is the Kindest Cut
Understanding this aspect of organizational systems and this definition of improvement, it becomes obvious that the projects that should be highest on the portfolio list should be those that address or support the major constraint.