System Migration & Revamp

Capability

Obsolete DCS and PLC migrationwith the plant running.

Every plant reaches the point where the spares are gone, the engineering software no longer runs and the last person who understood the logic has retired. ATG migrates those systems — including the legacy base others will not touch — and, where the source has been lost, reverse-engineers it.

The old system leaves. Production does not.

What ATG delivers

Scope we takeunder our own contract.

  • Migration study: as-found audit, I/O and logic recovery, risk assessment and cutover strategy.
  • Logic conversion and HMI redevelopment with a documented functional equivalence check.
  • Hot cutover planning — loop-by-loop or area-by-area — with rollback and bypass management on operating plant.
  • Supervisory and HMI migration: legacy SCADA to WinCC, AVEVA, FactoryTalk or zenon without changing validated controller logic.
  • Reverse engineering where source code, documentation or vendor support no longer exist.
  • Decommissioning, appropriate disposal and updated as-built documentation.

Platforms and vendors supported

  • Siemens Moore QUADLOG & APACS
  • Honeywell TDC 3000
  • Yokogawa CENTUM CS3000
  • Rockwell PLC-5 & SLC 500
  • Siemens S5
  • Schneider Modicon Quantum
  • GE Mark V
  • Triconex Tricon
  • Sensys Intellimax and other legacy SCADA

Standards applied

  • IEC 61511 (MOC and validation for safety functions)
  • ISA 101 / 18.2 (HMI and alarms)
  • Client MOC procedures

Typical scope of work

From the first meetingto the handover dossier.

The old system leaves. Production does not.

  • AuditAs-found survey, I/O recovery, logic and document recovery, obsolescence and risk register.
  • ConvertLogic translation, HMI rebuild, network and cabinet design, simulation and FAT.
  • Cut overStaged hot cutover with rollback, bypass management and witness points.
  • ClosePerformance verification, decommissioning, disposal, as-builts and training.

Where we work

Al-Khobar to Yanbu,and on rotation worldwide.

Kingdom of Saudi Arabia

Own Saudi entity and employer file; established mobilisation to Al-Khobar, Dammam, Jubail, Yanbu, Jeddah, Rabigh, Riyadh. Works under the client or plant project insurance.

International

Engineering and commissioning teams under long- and short-form agreements — residential, rotational and offshore — supported from Al-Khobar and Lahore.

Related projects

Claim,then evidence.

All 79 references
In-Kingdom
Saudi Water Authority — Yanbu Phase III

Yanbu Phase III — emergency diesel generator, jetty and metering gateway re-engineering

Saudi Arabia2025–2026
In-Kingdom
Arab Steel Company, Dammam

Steel melt shop HMI replacement and WinCC V8.1 upgrade

Saudi Arabia2025–2026
In-Kingdom
MODON / Tawzea

WWTP Jeddah Industrial City 3 upgrade, approx. 300 I/O

Saudi Arabia2024–2025

Frequently asked

Questions buyers askbefore the shortlist.

Which obsolete platforms have you migrated?

Rockwell SLC 500 to Siemens S7-1500 on a polyester dryer at Lucky Core Industries with cutover on a running plant; Sensys Intellimax SCADA to a PC-based supervisory system at Japan Power; steel melt shop HMI to WinCC V8.1 at Arab Steel, Dammam; and Siemens S7-400H emergency generator control re-engineering at Yanbu Phase III.

What does hot cutover mean in practice?

The new system is installed and tested alongside the old one, then loops or areas are transferred in planned steps with the plant producing, each step with a rollback path and a bypass record.

Can you recover logic when the vendor software is gone?

Usually, yes. We reverse-engineer from controller memory, wiring and operating records into a documented functional specification, then rebuild and verify.

Start a conversation

Tell us whatyou need built.

Send the scope, the P&IDs or just the problem. A control-systems engineer — not a sales desk — replies from Al-Khobar, normally within one working day.

Al-Khobar head office

+966 59 350 1825 · +966 53 849 2308
Proposals sales@atgpa.com
General inquiries@atgpa.com
Technical support techsupport@atgpa.com
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