A piping system can be fully installed and still not be ready. In most construction projects that is an academic distinction. In a data centre it is the difference between delivering on time and not.

Progress that looks like progress

Metres of pipe. Pumps installed. Equipment delivered and set in place. These are numbers that can be reported, and they look like progress in a project meeting.

The problem is that they answer the wrong question. “Is it installed?” is easy to measure. “Is it ready?” is what decides whether the plant can be put into operation.

Ready means ready to be tested, verified, commissioned and to carry uptime. A system can be one hundred per cent installed and zero per cent ready.

Mechanically complete is not commissioning-ready

Mechanical completion says the components are in place and connected. Commissioning-ready says the system can go through testing without surfacing something that should have been dealt with months earlier.

The gap between those two states is where data centre projects lose time. Not because anyone was careless with the installation, but because readiness was treated as a phase at the end instead of a requirement throughout the build.

Typical findings in that gap: pipework clean enough to look finished, but not clean enough to run water through. Documentation missing the actual test results. Components without traceable marking. None of this stops installation. All of it stops commissioning.

When does commissioning really start?

The usual answer is: when the plant is finished and about to go into operation.

That answer is why commissioning so often becomes the critical phase. The work starts at the point where pressure is highest, margins are smallest and the problems are already built in.

The better answer is: from day one. From design. From procurement. From the first prefab module, the first pipe, the first valve, the first weld.

That is not a rhetorical point. It is a construction method. Every early decision makes commissioning either easier or harder, and those decisions are made long before anyone thinks about the test phase.

What it means in practice

Building commissioning-ready moves work forward in time, to where it is cheapest to do.

Control in the workshop rather than on site. Testing and verification before systems leave a controlled environment. Internal cleanliness as a documented condition, not an assumption. Protection during transport and storage, because a clean system left open on site for three weeks is no longer clean. Documentation built up along the way instead of assembled at the end.

This is also the main argument for moving more of the work into the workshop. See what decides whether prefab pays off in a construction project.

None of this is new in itself. What is new is the requirement that it is in place before the system is fully installed – not afterwards.

Why data centres are different

In an office building, a delayed test phase can be absorbed. Move-in is postponed, the tenant waits, and the project carries on.

A data centre has no such slack. Build times are short, power density is high, and all the value lies in operational capacity. A delay in commissioning is not just a technical delay – it hits readiness, capacity and uptime. That is the delay the client actually measures.

That is why data centre projects cannot tolerate a construction method where readiness is something you come back to.

If commissioning turns into troubleshooting, you are already too late

That is the shortest way to put it. Commissioning is meant to confirm that the system works. The moment it is used to find out why it doesn't, the time that should have been buffer has become time spent on repairs.

The question a project should ask itself long before the test phase is not whether the systems will be finished.

It is whether they will be ready.