Darling & Whitty (2016) note that the definition of the PMO's function has evolved over time: Often, PMOs base project management principles on industry-standard methodologies such as PRINCE2 or guidelines such as PMBOK.
The survey indicates that operating an established PMO is one of the top three factors that drive successful project delivery.
Hobbs & Aubry (2010) identify 27 distinct functions of PMOs, highlighting a number of these that were found to not correlate with enhanced project performance.
Darling & Whitty (2016) state there is a need for evidence-based management practice, that consultants and practitioners are providing unproven solutions in which organizations both public and private are investing enormous quantities of finance without assured outcome.
Portfolio management offices have the added responsibility of supporting organizations in achieving strategic goals[14]