Project Portfolio Management (PPM) is a methodology to analyze and manage projects. PPM provides the foundation to take your ideas and render them as value-generating products. These ideas can come from your customer. Others can be internally generated through research or technical innovation.
Inevitably there will be many proposals, and, also inevitably, a limit on the time and resources at your disposal.
PPM provides the means to help your organization evaluate which projects to pursue, and how to execute them correctly: in time, and within budget.
There are two parts of your enterprise, each located at the beginning and end of your project process. The first is the strategic decision-makers. This group creates the strategy and vision. The second is the execution team. These guys work very hard to deliver the vision for the due date and under budget, usually employing Waterfall, Lean or Kanban methods.
Successful PPM will get these two groups working for each other. Teaming these people up effectively will deliver the right things to your customer at the right time. Good PPM evolves into a lifecycle. New proposals are always arriving for consideration and approval, current projects are somewhere in the execution stage, and successfully delivered projects need to be maintained and, if necessary, fixed.