Project Portfolio Management (PPM) is the centralized management of the processes, methods, and technologies used by project managers and project management offices (PMOs) to analyze and collectively manage current or proposed projects based on numerous key characteristics. The objectives of PPM are to determine the optimal resource mix for delivery and to schedule activities to best achieve an organization’s operational and financial goals ? while honouring constraints imposed by customers, strategic objectives, or external real-world factors. — Wikipedia
From PMI (Project Management Institute) :
What is a portfolio?
A portfolio is a collection of programs, projects and/or operations managed as a group. The components of a portfolio may not necessarily be interdependent or even related—but they are managed together as a group to achieve strategic objectives.
What is portfolio management?
Portfolio management is the centralized management of one or more portfolios, which includes identifying, prioritizing, authorizing, managing, and controlling projects, programs and other related work to achieve specific strategic business objectives.
How does portfolio management differ from project management and program management?
Portfolio, program and project management are all aligned and driven by organizational strategies. However, each one contributes differently to the achievement of strategic goals.