Commissioning builds on the construction phase, usually with the same disciplines but using a process based hierarchy to determine and report on progress. The style of testing changes, for example hydro-testing of piping, flange management and pre-commissioning and commissioning tests for the other disciplines.

As commissioning progresses, certificates are required based on completed work within a level of the process hierarchy. Completions Connect provides Tollgate functionality for this purpose. Defect (punch) management carries on and is used in concert with the tollgate to ensure milestones are achieved against the correct rule set.