A collection of projects or programs and other work that are grouped together to facilitate effective management of that work to meet strategic business objectives. The projects or programs of the portfolio may not necessarily be interdependent or directly related. (PMI 2008)
PMI. 2008. A Guide to the Project Management Body of Knowledge (PMBOK® Guide), 4th ed. Newtown Square, PA, USA: Project Management Institute (PMI).
See also project and program.