Control system commissioning proves that a DCS, PLC, SCADA or safety system works on the real plant before you depend on it. We run FAT and SAT, pre-commissioning, loop checks, function tests and SIS validation for all control system types across the UAE, the GCC and Europe, and hand over a complete signed dossier.
Control system commissioning is the work that proves an installed automation system does what the design says, on the real plant, before anyone relies on it. It starts with factory testing and ends when operations sign for the system. In between sit mechanical completion, pre-commissioning, loop checks, function tests, safety system validation and startup.
A control system can pass every software test in a factory and still fail on site. A transmitter is wired to the wrong channel. A valve strokes backwards. A fibre is patched into the wrong switch port. A safety trip fires on the wrong permissive. Commissioning is how those faults are found and fixed in a controlled order, with records that show each item was tested and accepted.
We commission all common control system types: distributed control systems (DCS), programmable logic controllers (PLC), SCADA and remote telemetry, safety instrumented systems (SIS), fire and gas systems, power management systems, and the instruments and field networks that connect them. We work across Siemens PCS 7, S7-400H, S7-1500 and ET 200SP HA, and we also work with platforms from Rockwell, Schneider, ABB, Emerson, Honeywell and Yokogawa. The method is the same whatever the logo on the cabinet.
The system is installed to the approved drawings. Cabinets are fixed, cables are glanded and terminated, earthing is done and hazardous area equipment is inspected. Nothing is energised for process use yet.
Static and de-energised checks, then first power-up. Cable insulation resistance, continuity, earth checks, power supply tests, cold loop checks and network verification. The output is a ready for commissioning certificate.
Dynamic tests with the system live. Hot loop checks, control and sequence function tests, cause and effect testing, SIS validation and failover tests, usually with utilities or inert media in the plant.
The first introduction of process fluids or energy. Control loops are tuned, alarms are rationalised against real conditions and the operators run the plant with commissioning engineers beside them.
The plant runs at agreed conditions for an agreed period to prove capacity, control performance and availability. Results are measured against the contract, not opinion.
Care, custody and control pass to the owner. The commissioning dossier, as-built drawings, final software backups and the open punch list go with it.
IEC 62381 defines three acceptance tests for process automation systems: the factory acceptance test (FAT), the site acceptance test (SAT) and the site integration test (SIT). Each answers a different question, and skipping one moves its faults into a more expensive phase.
| Test | Where and when | What it proves |
|---|---|---|
| FAT | At the integrator's or vendor's works, before shipping. Field I/O is simulated or wired to test panels. | Hardware is built to the drawings, software matches the functional design, I/O counts and spares are right, redundancy works and the HMI is complete. IEC 62381 |
| SAT | On site after installation and pre-commissioning, with the real field devices connected. | The system survived transport and installation, every loop works end to end, and FAT punch items are closed. IEC 62381 |
| SIT | On site, once the individual systems pass SAT. | Systems from different suppliers talk to each other correctly: DCS to SIS, PLC packages to DCS, PMS to switchgear, and links to remote control centres. IEC 62381 |
| SIS validation | On site, after SAT of the safety system and before hazards are introduced. | The installed SIS meets the safety requirements specification, including trip points, response times and bypass handling. IEC 61511-1 cl. 15 |
Every inspection and test generates punch items. Most projects grade them by what they block. The exact definitions sit in the project completion procedure, but the common pattern is:
On large projects the tests are tracked in a completion management system, often GoTechnology, Omega or a client in-house database, or a structured spreadsheet on smaller jobs. The plant is broken into systems and subsystems. Each tag carries its check sheets: A sheets for construction and mechanical completion, B sheets for pre-commissioning and commissioning, in the common naming used on oil and gas projects. When every sheet in a subsystem is signed and no A punch items remain, the subsystem moves to the next gate. The signed sheets, certificates and test records become the commissioning dossier handed to the owner.
Loop checks are the core of instrument and control commissioning. A loop check proves the whole signal path, from the field device through junction boxes, marshalling, I/O card and controller to the HMI tag and alarm, and back out again for outputs. IEC 62382 sets out how electrical and instrumentation loop checks should be done.
Done de-energised. Each core is tested for continuity and correct termination against the loop drawing, and insulation resistance is measured between cores and to earth. Screens are checked as earthed at one end only. This finds wiring faults before power is applied.
Done with the system powered. A signal is injected or simulated at the field end and read at the HMI. Outputs are driven from the HMI and the field device is watched. Alarms, trips and engineering units are confirmed for every tag.
A HART communicator or asset management software reads each smart transmitter's tag, range, units, damping and failure mode. These must match the instrument datasheet and the controller configuration, or the loop will read wrong with no visible fault.
| Injection point | 4 to 20 mA signal | What we check |
|---|---|---|
| 0% | 4.0 mA LRV | HMI shows lower range value. Low alarm and low trip states as designed. |
| 25% | 8.0 mA | Linear scaling. Reading within the agreed tolerance, often plus or minus 0.5% of span. |
| 50% | 12.0 mA | Mid-scale reading. For square root flow loops, check where the extraction is done: transmitter or controller, never both. |
| 75% | 16.0 mA | Scaling holds. High alarm thresholds approached and confirmed. |
| 100% | 20.0 mA URV | Upper range value shown. High alarm and trip states correct. |
| Fault | below 3.6 mA or above 21 mA NAMUR NE43 | Controller flags bad quality, the alarm raises and any trip acts on its configured fail-safe direction. |
For control valves the test runs the other way. The output is set at 0, 25, 50, 75 and 100% and the valve position is confirmed at the valve and on the positioner feedback. Open and closed limit switches, stroke time, fail position on loss of air and on loss of signal are all recorded. For digital inputs, each switch is operated at the field device, not shorted at the junction box, wherever access allows.
Once loops are proven, the control logic is tested as a whole. PID loops are checked for direction of action, setpoint tracking and bumpless transfer between manual and auto. Sequences are stepped through, including holds, aborts and restarts. Interlocks and permissives are proved by simulating each condition, not by reading the code. Motor control is tested from the HMI and local station with the MCC in test position first.
Safety and shutdown logic is usually specified as a cause and effect matrix. Each row is an initiating cause, such as a high-high pressure or a confirmed gas detection. Each column is an effect, such as closing a shutdown valve or tripping a pump. The test applies every cause in turn and confirms every marked effect, and also confirms that unmarked effects do not act. Voting logic such as 2oo3 is tested with one, two and three inputs tripped. Every cell is signed. On fire and gas systems the same matrix drives alarms, beacons, HVAC dampers and suppression release.
Two kinds of test protect people and uptime: validation of safety instrumented functions, and proof that redundant controllers, networks and power supplies take over when one side fails. Both must be done on the installed system, not assumed from the FAT.
IEC 61511-1 separates SIS installation and commissioning (clause 14) from SIS safety validation (clause 15). Validation confirms that each safety instrumented function (SIF) works as written in the safety requirements specification: correct sensors, trip setpoints, voting, final elements, response time and safe state. It also tests bypasses, overrides, resets, diagnostics and the response to a detected fault. Validation must be complete before the hazard it protects against is present.
Proof test procedures written for operation (clause 16) should be trialled during commissioning. If a procedure cannot be followed on the real plant, it is better to find out now than at the first proof test interval. The validation records, with the as-left software version and checksum of the safety logic, form part of the functional safety records.
Redundancy that has never been tested is a guess. Failover tests remove one element at a time while the process, or a simulation of it, is running, and record what the operator sees:
We carried out control system commissioning on TenneT's 980 MW HVDC offshore converter platform, built by McDermott at its Jebel Ali yard in Dubai. The platform connects German North Sea offshore wind farms to the grid.
Redundant Siemens S7-400H controllers with CPU 410-5H, PS 405 and CP 443-1. KE0001 runs integrated monitoring and control (IMAC). KE0002 runs the power management system (PMS). ET 200SP HA distributed I/O over PROFINET and LC multimode fibre.
SCALANCE XF204-2BA and XF204-2BA DNA switches for PRP redundant networks. SITOP PSU6200 trains with a SITOP RED1200 redundancy module and E-T-A REX12D electronic circuit breakers. Interface relay marshalling with push-in terminals and IEC 81346 designations on every device.
A system like this shows why failover testing has to be planned layer by layer. Each redundant CPU pair, each PRP network, each 24 V DC train and each electronic breaker channel is a separate test with its own expected result. Consistent IEC 81346 reference designations made it possible to trace every device from drawing to cabinet to test sheet without ambiguity.
Client specifications usually call up these standards. We write test procedures that reference the clauses that apply, so the test record stands up to audit.
FAT, SAT and SIT for automation systems in the process industry: scope, documents and responsibilities.
Phases and milestones for commissioning electrical, instrumentation and control systems in the process industry.
Electrical and instrumentation loop checks, from installation checks to the functional loop test.
SIS lifecycle for the process sector, including installation, commissioning, safety validation and proof testing.
Functional safety of E/E/PE safety-related systems. Basis for the SIL capability of SIS hardware.
Design and installation of electrical equipment in explosive atmospheres, and its initial and periodic inspection.
Parallel Redundancy Protocol (PRP) and HSR for seamless failover of industrial Ethernet.
Alarm philosophy, rationalisation and performance, checked during commissioning and startup.
Standard 4 to 20 mA failure signalling levels used to set and test transmitter fault detection.
We follow the same sequence on a single PLC package or a multi-system platform. The scale changes. The gates do not.
Every test leaves a signed record. These are the documents that make up a complete commissioning dossier.
| Document | Content |
|---|---|
| Commissioning plan | Systems breakdown, sequence, gates, resources and responsibilities. IEC 62337 |
| FAT, SAT and SIT procedures and reports | Approved procedures, signed results, deviations and punch lists. IEC 62381 |
| Loop check sheets | Per-tag cold and hot loop records, injection readings, HART configuration and valve stroke data. IEC 62382 |
| Cable test records | Insulation resistance, continuity and fibre loss results by cable number. |
| Cause and effect test records | Signed matrix with every cause and effect cell tested. |
| SIS validation report | SIF by SIF results against the safety requirements specification, with logic version and checksum. IEC 61511-1 cl. 15 |
| Redundancy test report | Controller, network and power failover results and recovery times. |
| Punch list and completion certificates | Mechanical completion, ready for commissioning and handover certificates with the final A, B and C status. |
| Software and as-builts | Final project backups, as-built loop drawings, I/O list and marked-up cabinet drawings. |
We have worked in the region for more than 17 years, from Dubai and Abu Dhabi to Saudi Arabia, Qatar, Oman, Kuwait and Bahrain. Gulf sites change how commissioning is planned and what it must check.
Summer shade temperatures pass 45°C and cabinets in the sun run far hotter. We check panel cooling, power supply and I/O derating and the temperature rating of field devices before energising, and plan outdoor hot loop checks for the cooler hours.
Fine dust gets into open cabinets and connectors during construction. Coastal humidity causes condensation overnight. We check IP ratings, gland sealing, anti-condensation heaters and cleanliness at mechanical completion, and keep fibre ends capped until patching.
Oil and gas sites need Ex inspection to IEC 60079-17 before energising. Clients such as ADNOC, Saudi Aramco, QatarEnergy and PDO set their own completion and handover procedures. We write our check sheets to the client's system rather than ask the client to adopt ours.
Commissioning goes best when the same engineers know the design. For new systems see our PLC, DCS and SCADA system integration and turnkey control system projects. For field device work before loop checks, see instrumentation installation and calibration. If a commissioned system is misbehaving, our control system fault finding team can help. To staff a large job, see our commissioning teams, or contact us to discuss your project.
Short answers to what clients ask us most. For anything specific to your plant, talk to an engineer.
It is the structured testing that proves an installed control system works as designed on the real plant. It runs from factory acceptance testing through mechanical completion, pre-commissioning, loop checks, function tests and startup to handover. Every step leaves a signed record.
A factory acceptance test (FAT) checks the hardware and software at the supplier's works before shipping, usually with simulated I/O. A site acceptance test (SAT) repeats the key checks on site with the real field devices connected, after installation. IEC 62381 defines both, plus the site integration test (SIT) for interfaces between systems.
Pre-commissioning covers static and de-energised checks such as insulation resistance, continuity, cold loop checks and first power-up. Commissioning is dynamic testing with the system live, such as hot loop checks, function tests and cause and effect tests. Pre-commissioning ends with a ready for commissioning certificate.
A cold loop check tests the wiring with power off: continuity, correct terminations and insulation resistance. A hot loop check is done with the system powered, injecting a signal at the field device and confirming the reading, alarms and trips at the HMI. Analogue loops are normally checked at 0, 25, 50, 75 and 100 percent of range.
Punch items are graded by what they block. A items must be closed before the next completion gate, B items can be carried forward but must be closed before startup or handover, and C items are minor and can be closed after handover by agreement. The exact rules are set in each project's completion procedure.
IEC 61511 requires SIS safety validation on the installed system before the hazard is present. Each safety instrumented function is tested against the safety requirements specification, including trip setpoints, voting, final element action, response time, bypasses and resets. The results and the logic version are recorded in the validation report.
It depends on the I/O count, the number of systems and interfaces, and site readiness. A single PLC package may take days, while a large platform with several redundant systems takes months. A thorough FAT and a clear completion system shorten site time more than anything else.
Yes. We work across the UAE, Saudi Arabia, Qatar, Oman, Kuwait and Bahrain, as well as Europe. We can supply individual engineers or full commissioning teams of 50 or 100 people with their own supervisors.
Tell us what system you have, where it is and what stage the project has reached. We will come back with a commissioning approach, team size and programme. Call +971 54 774 6012 or message us on WhatsApp at +44 7746 964222.
