In our previous article, Before, During and After Go-Live: Commissioning, Site Acceptance Testing (SAT) and Data Centre Audits Explained, we looked at three important checkpoints in the data centre lifecycle:
Before go-live: Commissioning
During go-live: Site Acceptance Testing (SAT)
After go-live: Data centre audits
Each has a different job to do.
In this edition, we're taking a closer look at the first stage: commissioning.
Because before you test whether an entire data centre can withstand real operating conditions, you first need confidence that the individual systems supporting it have been installed, configured and started correctly.
And in a critical environment, "installed" and "ready" are not necessarily the same thing.
What Does Data Centre Commissioning Actually Mean?
Commissioning is a structured process used to verify and document that equipment and systems have been installed and configured correctly and perform in accordance with the project requirements.
Industry guidance from ASHRAE describes commissioning as a quality-focused process designed to verify that a facility and its systems meet the Owner's Project Requirements. Importantly, it isn't simply a final inspection at the end of construction. Good commissioning extends across project delivery and provides a documented path from design intent through installation, testing and operation.
For a data centre or critical infrastructure environment, that can involve systems such as:
- UPS and battery systems
- Power distribution
- Cooling and HVAC equipment
- Racks and supporting infrastructure
- Monitoring and control systems
- Electrical and mechanical services
- Structured cabling and associated infrastructure
The exact commissioning scope will depend on the project.
But the question we're ultimately trying to answer is the same:
Has what was designed and specified actually been installed, configured and prepared correctly?
That sounds straightforward. In practice, it's where seemingly minor issues can have significant consequences.
Why Commissioning Matters So Much in a Data Centre
A commercial building can sometimes tolerate a fault without immediately affecting the organisation operating inside it.
A critical environment has far less room for error.
Uptime Institute's 2024 Global Data Center Survey found that on-site power distribution was the primary cause of 54% of respondents' most recent impactful data centre outages.
Power was by far the largest category, ahead of cooling, IT systems and network failures.
That's important because power infrastructure isn't simply about whether electricity is available.
It is about whether the entire power chain behaves correctly when something changes.
- What happens when mains power is interrupted?
- Does the UPS respond as expected?
- Are batteries healthy and correctly configured?
- Does the load transfer correctly?
- Are alarms generated?
- Is the monitoring system reporting the correct condition?
- Are redundancy paths genuinely independent?
Commissioning begins establishing that confidence before the facility progresses into integrated Site Acceptance Testing.
Installed Doesn't Automatically Mean Commissioned
One of the most important distinctions to understand is the difference between installation completion and commissioning completion.
A UPS can be physically installed and connected, a cooling unit can be powered, a rack can be populated and monitoring platform can be online.
That does not automatically mean those systems have been configured correctly or are ready to support a critical production environment.
Commissioning looks beyond physical completion.
For a UPS installation, for example, this may include checking:
- Equipment against approved specifications
- Physical installation and clearances
- Input and output connections
- Battery installation and configuration
- Bypass arrangements
- Protection settings
- UPS operating parameters
- Alarm functionality
- Monitoring and communications
- Startup procedures
- Manufacturer requirements
- Documentation and labelling
The objective is to identify discrepancies while they are still relatively easy to rectify.
Finding a configuration issue before production begins is a commissioning item. However finding the same issue during an outage is an incident.
The Cost of Finding Problems Too Late
The later an infrastructure issue is discovered, the harder it can become to fix.
Before go-live, engineers generally have greater freedom to isolate equipment, change configurations, correct cabling, adjust controls and repeat testing.
Once production workloads are running, the equation changes.
Now there may be:
- Change windows to negotiate
- Customers or internal users to protect
- Redundancy that cannot easily be taken offline
- Business-critical applications running
- Increased safety and operational considerations
- After-hours works
- Additional approvals and risk assessments
A defect that may have required a straightforward correction during commissioning can become significantly more disruptive once the environment is operational.
This is why commissioning should not be viewed as another box to tick before handover.
It is an opportunity to find problems while you still have the safest and least disruptive opportunity to fix them.
Commissioning Is Becoming More Important, Not Less
Modern data centres are becoming more complex.
Higher rack densities, greater power requirements, more sophisticated cooling technologies and increasingly interconnected monitoring and control systems mean there are more dependencies to consider.
ASHRAE's guidance for modern data centre environments describes commissioning in progressive stages, from verifying equipment and installation through pre-functional checks and functional performance testing, before ultimately moving into integrated systems testing.
It also highlights an emerging challenge: pressure to deploy infrastructure faster can place commissioning activities at risk of being compressed toward the end of a project.
That's exactly when commissioning needs to remain disciplined.
Speeding up deployment is valuable. Discovering after handover that critical infrastructure wasn't properly configured isn't.
What Should a Good Commissioning Process Look Like?
The detail will vary according to the equipment and project, but effective commissioning should be structured and documented rather than treated as a visual inspection and startup exercise.
1. Verify what has actually been installed
Equipment should be checked against project documentation, approved specifications and manufacturer requirements.
That includes model numbers, ratings, capacity, configuration and associated components.
Substitutions and project changes are common. Commissioning helps ensure the finished installation reflects what the organisation believes it has purchased and designed.
2. Inspect the physical installation
Equipment needs to be installed correctly before meaningful functional testing can occur.
Depending on the system, this may include checking electrical connections, mechanical installation, access and clearances, cabling, labelling, battery arrangements, airflow requirements and other installation conditions.
3. Verify configuration
Modern critical infrastructure is increasingly software and controls driven.
The hardware may be correct while the settings aren't.
UPS parameters, alarms, communications, thresholds, control sequences and monitoring integrations all need to reflect the intended operating environment.
4. Start and functionally test equipment
Individual equipment and subsystems should then be started and tested to confirm correct operation.
This is where the project moves from:
"It has been installed."
to:
"We have evidence that it operates correctly."
5. Record defects and rectify them
Good commissioning should create a clear record of issues identified, actions required and evidence of rectification.
A commissioning issue list isn't evidence that a project has failed.
Quite the opposite.
Finding defects before they reach production is one of the reasons commissioning exists.
6. Document the final condition
Commissioning should leave the owner with useful information.
Depending on the project, that can include commissioning records, configuration information, test results, equipment details, defect close-out records and updated documentation.
Those records become valuable later when equipment is maintained, upgraded, replaced or investigated following an incident.
Commissioning Also Establishes a Baseline
There's another benefit that is often overlooked.
Commissioning tells you what normal looked like when the infrastructure was new.
Correctly captured settings, operating parameters, alarm conditions and equipment information provide a baseline that can later be compared against the live environment.
That becomes particularly useful when investigating:
- Capacity constraints
- Cooling problems
- UPS or battery deterioration
- Alarm changes
- Equipment replacement
- Infrastructure upgrades
- Unexpected operating behaviour
Without that baseline, teams can end up trying to determine whether something has changed without having a reliable record of where it started.
Where Does Commissioning Stop and SAT Begin?
This is where the terminology can become confusing.
- Commissioning proves that the equipment and systems are correctly installed, configured and functioning.
- Site Acceptance Testing takes the next step. SAT asks what happens when those systems need to operate together under realistic operating and failure scenarios.
For example, commissioning may verify that a UPS starts correctly, its batteries are configured and its alarms function.
SAT may then test what happens to the wider environment when utility power is lost and multiple systems must respond in the correct sequence.
Think of commissioning as making sure every member of the orchestra knows how to play their instrument.
SAT is where you find out whether they can play the piece together.
We'll explore that in detail in the next article in this series.
When Should You Consider Commissioning?
Commissioning shouldn't be limited to an entirely new data centre.
It should be considered whenever new critical infrastructure is introduced or significant changes are made, including:
- New UPS installations
- UPS replacements or capacity upgrades
- New battery systems
- Cooling system installations or upgrades
- New racks and power distribution
- Data centre expansions
- New comms rooms or critical IT environments
- Infrastructure relocations
- Major electrical or mechanical upgrades
The more critical the environment, the stronger the case for independently verifying that infrastructure is ready before relying on it.
Don't Let Go-Live Become the Test
The worst time to discover a problem with critical infrastructure is when the infrastructure is being called upon to protect the business.
Commissioning gives project owners an opportunity to identify installation, configuration and functional issues before that happens.
It provides evidence that the infrastructure delivered to site isn't simply present and powered on, but has been systematically checked and prepared for the next stage of testing.
Because when production workloads are about to depend on your infrastructure, "it should work" isn't a particularly useful level of assurance.
You want to know it has been checked.
How Treske Can Help
Treske supports organisations with the commissioning of critical data centre infrastructure across new installations, upgrades and expansion projects.
Our team works across critical power, UPS, cooling, racks and supporting data centre infrastructure, helping organisations verify equipment installation, configuration and operation before environments progress to final acceptance and go-live.
We can also work with project managers, IT teams, facility managers, contractors and equipment vendors to identify issues early, document findings and help ensure infrastructure is genuinely ready for the next stage.
Whether you're commissioning a new data centre, replacing a UPS, expanding capacity or introducing new critical infrastructure into an existing facility, getting the first stage right can prevent far more difficult conversations later.
Planning a new installation or infrastructure upgrade? Speak with Treske about commissioning your critical infrastructure before go-live.
Next in the series: During Go-Live – Why Site Acceptance Testing Is Where Your Data Centre Proves Itself.