CONTROL INFRASTRUCTURE / TECHNICAL DELIVERY
Modernizing while operations continue.
Replacing end-of-life control and safety systems in plants that cannot stop.
PCS Singapore · About 2 min read
- My role
- Program lead for control-system migrations.
- Constraint
- The plants run continuously; every cutover had to fit a planned maintenance window.
- Decision
- Prove compatibility and a recoverable state before cutover, then verify and hand over.
- Outcome
- Zero downtime across the migrations.
- 01Map dependencies
Identify functions and interfaces.
- 02Prove compatibility
Acceptance evidence before transition.
- 03Transition & verify
Check the resulting system and handover.
Stop, resolve the gap or return to a recoverable state.
Illustrative transition framework: dependencies, acceptance evidence and handover.
PERSONAL CONTRIBUTION
What I contributed
- Led $10M+ in control infrastructure modernization across four legacy control and safety-system architectures.
- Directed a separate $5M+ program replacing 30+ end-of-life gas chromatographs.
- Ran technology evaluation, competitive vendor tenders and factory acceptance testing.
The situation
Control and safety systems in continuously operating petrochemical plants were approaching the end of their supported life across four legacy architectures. Stopping production to replace them was not an option, so every migration had to fit inside a planned maintenance window while the rest of the plant kept running.
What I did
At PCS Singapore, I led the $10M+ modernization program from technology evaluation and vendor coordination through factory acceptance testing and site implementation. I also directed a separate $5M+ program that replaced more than 30 end-of-life gas chromatographs, running a competitive tender and factory acceptance testing before installation.
The result
Every architecture was migrated with zero downtime. Consolidating legacy PLC control onto the distributed control platform also simplified maintenance and long-term lifecycle support.
The engineering principle
A platform change also changes ownership, support and operating practice. Compatibility, acceptance evidence and handover belong in the same plan.
INSIDE THE DECISION
What has to be true before a migration can proceed?
The gates I use before any cutover proceeds.
Retain the current platform
- What it offers
- Avoid an immediate transition.
- What it asks of the design
- Continue managing lifecycle and support constraints.
Modernize the platform
- What it offers
- Establish a supportable foundation.
- What it asks of the design
- Resolve compatibility, transition and handover risks.
Walk through the acceptance gates
Gate 1: Dependencies
Understand the dependencies and intended functions.
Gate 2: Compatibility
Demonstrate compatibility and acceptance criteria.
Gate 3: Recoverability
Define stop conditions and a recoverable state.
Gate 4: Handover
Agree on ownership and support at handover.
Acceptance gates
- Understand the dependencies and intended functions.
- Demonstrate compatibility and acceptance criteria.
- Define stop conditions and a recoverable state.
- Agree on ownership and support at handover.
A transition is credible when its evidence and support arrangements are understandable.
Terms used on this page
- DCS (distributed control system)
- The computer system that monitors and controls a continuously running plant, spread across many controllers rather than one central computer.
- PLC (programmable logic controller)
- A rugged industrial computer that controls a machine or part of a process with fast, repeating logic.
- Factory acceptance testing
- Testing equipment and its software at the supplier, against criteria agreed in advance, before it is shipped and installed.
- Cutover
- The moment operation switches from an old system to its replacement.
- Maintenance window
- A planned period when equipment may be taken out of service for work, agreed in advance with the people who run the plant.
- Gas chromatograph
- An analyzer that separates a gas sample into its components and measures how much of each is present.
Diagrams are conceptual and do not depict any employer system.