A rolling mill removed from the centre of a producing steel plant. Two live lines within twenty metres, a shared utility corridor along one elevation, and a caster whose intake could not tolerate dust ingress. Eleven months of work, zero unplanned outages.
None of that outcome came from the demolition method. It came from the interface plan.
What an interface plan actually contains
- A jointly owned register of every physical and operational interface between the work and the running plant
- Agreed segregation — physical, not procedural — at every boundary, with responsibility for maintaining it named
- Shared permit protocols so that our permits and the plant's permits cannot conflict
- Monitoring thresholds agreed with the people who own the affected equipment, not imposed by either side
- Defined communication routes including who can stop whose work, and how that instruction travels at 3am
- Pre-agreed windows for anything requiring a change to plant operation, fixed weeks in advance
The utility corridor example
The shared utility corridor running along the mill's north elevation supplied both operating lines. It had to be re-routed. That work required a fourteen-hour interruption, and the date was fixed nine weeks in advance in a joint planning session with the plant's operations, maintenance and production scheduling teams.
Nine weeks of notice on a fourteen-hour interruption is not caution. It is what allows a production plant to absorb the interruption without cost — and it is only achievable if the interface was identified early, which is what the register exists to do.
The failure mode to avoid
The common failure is treating the client's operations team as a stakeholder to be informed rather than a participant in planning. Informed stakeholders find out about interfaces late, when accommodating them is expensive. Participants find them during planning, when accommodating them is free.
Every interface found during planning is free. Every interface found during execution is not.
DDMS Global HSE
Health, Safety & Environment
16 October 2025 · 6 min read


