Factory and Site Acceptance Testing
Factory and site acceptance testing
When a plant buys a control system, the vendor writes the test procedure, the vendor runs the test, and the vendor decides what counts as a pass. The buyer signs. That arrangement works until something in the specification was never actually tested, and by then the system is installed.
We act for the buyer. We have written test procedures, witnessed factory acceptance tests at Emerson and at ABB, and run site testing on DCS, ESD and burner management systems on plants in operation.
Factory acceptance testing
Test procedures written against the specification. Not against the vendor's standard checklist. Every requirement in the functional specification becomes a test with a defined pass criterion, including the ones the vendor would rather demonstrate than test.
Simulation of the field. I/O forced and simulated across the full signal range, not only at the values that behave. Failure modes exercised: open circuit, out of range, communication loss, power loss to a segment.
Redundancy proved by failure. Controller changeover, network changeover and power supply changeover tested by removing the primary, under load, with the process simulation running — not by reading a status indication.
Safety system logic against the cause-and-effect matrix. Every input combination that the matrix defines, and the ones it does not, to establish what happens outside the specified envelope. See also Safety Systems and Burner Management Systems.
Punch list with severity. What blocks shipment, what can be closed on site, and what is a specification defect rather than a build defect. Recorded so that the same item cannot quietly change category later.
Site acceptance testing
Loop checking. Field device to control system to operator display, end to end, per loop, against the loop drawing.
Functional testing. Interlocks, sequences and permissives exercised against the control narrative, with the process in a defined state.
Loop tuning. Controllers tuned on the running process rather than left at the values that survived the factory test.
Safety system proof testing. Trip functions demonstrated from the sensor through the logic solver to the final element, with response times measured.
Documentation reconciled to reality. As-built drawings and signal database updated to what was actually installed, which is never exactly what was designed.
Independent verification
We also verify I&C design documentation against local and international standards on behalf of a buyer, whether or not we take part in the testing — before construction, when a finding still costs a drawing revision rather than a shutdown.
We have carried out this role at scale: on a combined cycle power plant, verification of design for execution documentation, review of control algorithms and signal databases, inspection of instrumentation and control equipment at the manufacturers under their quality control programmes, entrance control at site, quality control of erection and commissioning, and review of test and commissioning programmes — all as the investor's representative.
Independent expert review
We are also asked to review someone else's test results. In one case a completed functional test protocol for a turbogenerator — turbine governor behaviour, generation balancing, automatic synchronisation and 6.3 kV automatic transfer switching — was given to us for expert review, to establish what had not been demonstrated and where the conclusions did not follow from the measurements.
A test report is evidence only if the tests behind it prove what the report claims. Reading one properly is a separate skill from running one.
Platforms we have tested on
Emerson Ovation · ABB Industrial IT 800xA · ABB Symphony · Siemens PCS7 · Yokogawa Centum VP · HIMA HIQuad · Foxboro Triconex · ABB AC800