Failure to properly commission a data center leaves the door wide open for expensive and disruptive downtime that could have been avoided. Integrated commissioning of all physical infrastructure components assures maximum data center performance and justifies the physical infrastructure investment. This paper reviews the desired outputs and identifies the standard inputs of the commissioning data center project step. The commissioning process flow is described and critical success factors are discussed. The commissioning process inputs and outputs are also placed in context with other key data center project process phases and steps.