There are many opinions and practices some say PMOs must fulfill. The PMBoK 5th edition dedicates a page and a half to such discussion identifying 6 PMO functions. Hobbs & Aubry (2010) identified 27 distinct functions of PMOs highlighting a number of these were found to not correlate to enhanced project performance. Darling & Whitty (2016) state there is a need for evidence-based management practice, that consultants and practitioners are providing unproven solutions which organisations both public and private are investing enormous quantities of finance to without assured outcome, further the publication of opinions without scientific basis in the field of science, medicine or law would not be tolerated, and it is equally important for justification to be presented in the management field.