The project involved replacing legacy S5 PLC hardware with modern S7 systems while ensuring the new logic matched the behaviour of the existing control system prior to cutover.
Key challenges included:
The S5 and S7 PLCs were run simultaneously to enable side-by-side comparison.
Outputs from both PLCs were compared cycle-by-cycle, enabling engineers to:
Once the S7 logic demonstrated consistent and repeatable alignment with the S5 system, ISS executed a controlled cutover achieving the migration with zero unplanned downtime.
✔ Seamless transition from Siemens S5 to S7 PLCs
✔ No unplanned production loss
✔ Improved reliability, maintainability, and lifecycle support
✔ Standardised control platform across upgraded systems
✔ Reduced risk associated with obsolete automation hardware
This project demonstrates how ISS supports manufacturers in modernising critical automation systems while maintaining productivity and operational continuity.
Success on a site as complex as MM Kembla requires a multi-disciplinary approach. This project saw a collaborative effort from the ISS engineering core:
