Kasper Munkholm
Head of Projects, Partner
What is commissioning?
What is commissioning?
If you work with industrial projects, energy, data centers, or other complex technical installations, you have probably come across the term commissioning.
But what is commissioning, exactly?
Commissioning is the process of making sure that systems, equipment, and installations are tested, verified, and ready to operate safely and as specified by engineering while also being documented against design and operational requirements. In other words, commissioning means checking that a plant, system, or technical installation actually works as intended and is in compliance before it goes live.
That is why commissioning is often described as the final quality and readiness check in a project.
In practice, commissioning is the step between installation and operation. It is where project teams confirm that individual components work, that systems work together, and that the facility is ready for handover. In some companies, however, commissioning is introduced as early as in the design phase.
Why is commissioning important?
For project owners, EPCs, and contractors, commissioning is a critical phase. When it is done properly, it reduces risk, improves safety, and creates a smoother transition from construction to operation.
Commissioning is important because the final project phase is often where pressure is high.
Schedules are tight, multiple disciplines are working in parallel, and even small errors can delay handover or create operational problems later on.
A structured project commissioning process helps you:
- confirm that systems operate as intended
- identify faults before startup
- improve safety during handover
- reduce delays and rework
- create better documentation for operations
- support a smoother start to production or facility use
In other words, commissioning helps turn a completed installation into an operational facility.
What happens during commissioning?
The commissioning process varies from project to project, but it often includes a combination of technical checks, coordination, and documentation.
Typical commissioning activities include:
- verification of system completion
- functional testing of equipment
- checking controls, alarms, and signals
- interface testing between systems
- troubleshooting and issue resolution
- readiness reviews before startup
- support for documentation and handover
The goal is not just to prove that one component works on its own. The goal is to prove that the full system works reliably under real operating conditions.
In large technical projects, project commissioning often requires close coordination between site management, technical specialists, contractors, and operations teams.
What is the difference between pre-commissioning and commissioning?
This is one of the most common questions in technical projects.
Pre-commissioning
Pre-commissioning takes place before full commissioning starts and is the mechanical completion and basic verification of a new system setup or piece of equipment.
This phase typically includes preparatory work such as cleaning, flushing, leak testing, loop checks, calibration, inspections, and punch list follow-up. Pre-commissioning also includes verificatory practices such as calibration, I/O testing and loop checks. The purpose is to make sure the system is ready for live functional testing.
Commissioning
Commissioning includes functional and integrated testing in operation-like conditions.
This is where teams perform operational testing in which you test pressure control, alarms, positioning of valves, and dataflow to figure out whether or not systems are working together properly (master/slave).
verify performance, system logic, safety functions, and interfaces between disciplines. It is also where documentation is confirmed, and outstanding issues are pushed toward closure.
Put simply:
Pre-commissioning prepares and verifies the system.
Commissioning tests the system.
What is plant commissioning?
Plant commissioning refers to commissioning activities carried out in industrial facilities such as process plants, manufacturing sites, utilities, energy facilities, or other complex technical plants.
Plant commissioning often involves multiple disciplines working together, including mechanical, electrical, automation, instrumentation, and operations teams. Because of this, plant commissioning requires strong planning, clear responsibilities, and close follow-up during the final project phase.
In practice, plant commissioning is about making sure that the full plant is safe, functional, and ready for operation.
What is a commissioning engineer?
A commissioning engineer is a technical professional with the responsibility of planning, coordinating, testing, and verifying systems during the commissioning phase. Each commissioning engineer usually has their own system and is responsible for the correct testing and documentation of that system in accordance with standards and design.
A commissioning engineer may be involved in:
- reviewing system readiness
- supporting testing and verification
- coordinating technical interfaces
- identifying and resolving issues
- following up on documentation
- helping prepare systems for handover and startup
In complex projects, a commissioning engineer plays an important role in making sure that systems perform as intended and that the commissioning process stays structured and on track.
Why use external commissioning support?
Many companies bring in external commissioning support when a project enters a critical final phase.
This is especially relevant when:
- the schedule is under pressure
- internal teams are already stretched
- specialized commissioning experience is missing
- the project involved multiple technical interfaces
- extra control is needed during handover
An experienced commissioning engineer can help keep activities moving, follow up on open points, coordinate stakeholders, and create more confidence around the transition from construction to operation.
how plant supervision can help
Plant Supervision helps companies strengthen the commissioning phase by providing experienced technical professionals for complex projects. Whether you need support with site coordination, supervision, project commissioning, plant commissioning, or an experienced commissioning engineer, we help you find the right profile for the task.
Looking for commissioning support?
Contact Plant Supervision to learn how we can help you strengthen your project team and support a smoother handover to operation.
FAQ
Commissioning is the process of testing and verifying that systems and equipment are installed correctly and ready to operate safely and as intended.
The purpose of commissioning is to reduce risk before startup, confirm system functionality, and support a smoother handover to operations.
Pre-commissioning prepares the system through checks and cleaning activities. Commissioning verifies that the system functions correctly in practice.
Commissioning in construction is the process of verifying that building systems and technical installations are complete, tested, and ready for handover and operation.
Plant commissioning is the commissioning of industrial systems and facilities to confirm that the plant is safe, functional, and ready to operate.
A commissioning engineer is a technical specialist who supports testing, verification, coordination, and readiness during the commissioning phase.
Commissioning helps identify issues before operation, improves safety, reduces delays, and ensures systems perform according to design.
