The commissioning of new plants is a fundamental part of the energy production process, the objective of this article is to present a methodology that allows Improving the Commissioning of wind and solar photovoltaic plants, for this the ISO 55000: 2014 and ISO 14224 standards were taken: 2016 and this results in a four-phase methodology:Phase 1: ISO 14224 Taxonomy Standard.Phase 2: ISO 31000 Standard Criticality.Phase 3: RCM (Reliability Centred Maintenance) Methodology.Phase 4: Contributions of the phases to the requirements of the ISO 55001 standard.It is concluded that by applying this methodology the commissioning of wind and solar photovoltaic plants is improved