The Global Environment Facility (GEF) is one of the most thoroughly evaluated international organizations. Its pilot phase was evaluated by an external independent evaluation. When the restructured GEF took shape, external independent evaluation became the norm for every replenishment period, with an
overall comprehensive study of the Facility’s performance undertaken to inform the
next replenishment cycle. At first, these performance studies were outsourced and
undertaken by evaluation teams or firms specifically hired for the purpose. After the
GEF’s Independent Evaluation Office was set up, the overall performance studies
(OPSs) were taken up by that Office, and the Fifth Overall Performance Study (OPS5) is
the second executed by it.