More and more, project managers are being tasked with managing multiple projects within an organization, which can take the form of a project portfolio. Managing this portfolio effectively is key to the success of the organization... and the project manager. However, substantial questions persist about truly effective project portfolio management. (1) How do you define "effectiveness"?; (2) How do you measure it?; (3) What are the critical factors that impact success? Join project management researcher-practitioners from Pennsylvania State University and the Stevens Institute of Technology as they go inside five different organizations from across the business spectrum in search of the answers. These dramatically different organizations, which ranged from financial services and telecommunications, to technology and government-based R&D, all shared one thing: the reliance upon effective project portfolio management for their success. In this landmark study, researchers were granted unprecedented access to reams of internal project documentation and hours of one-on-one time with key personnel, from C-Suite and project management executives to front-line staff. This enabled the team to assemble the inside story of how project portfolios were actually managed in each of these organizations, and identify what worked and what didn't. Using this understanding and a comprehensive literature review as a foundation, they created an empirically grounded definition of project portfolio management effectiveness that can be applied to organizations of all kinds. They were then able to identify the five critical process, organizational, and human factors that impact project portfolio management effectiveness and propose common-sense criteria for accurately measuring it.