Retrofitting a legacy Kwai Chung or Tsuen Wan hall from 5–15 kW/rack to 40 kW+ is not a cooling upgrade. It is a re-architecture of the blast radius.
Power density changes which assets sit on the critical path. Busway, PDU, CRAH, CDU and even the floor loading model shift consequence scores. What was Class C under legacy loads can become Class A overnight — and if your Asset Criticality Rating still reflects 2019, your PM regime is protecting the wrong things.
The ACR step exists exactly for moments like this. New equipment inherits parent status in the hierarchy, but its Safety, Environment, Reputation and Financial scores are almost always higher than the equipment it replaces.
We run a facilitated ACR workshop after hierarchy refresh and before FMEA. The output is a ranked list of what breaks first — financially and operationally — under the new density. That list drives spares, standby, inspection intervals and which scenarios enter the OR-2 / resilience library.
Operators who skip the refresh usually discover the shift the hard way, when a class-C-in-old-life asset turns out to be class-A-in-new-life during a summer peak or a concurrent maintenance window.
If you have a density programme on the roadmap, schedule ACR as a gate — not an afterthought. Capex without criticality is just a more expensive outage calendar.
- Density changes blast radius — refresh ACR before FMEA.
- Legacy Class C assets often become Class A under AI loads.
- Use ACR output to drive spares, standby and scenario libraries.
- Gate the retrofit: hierarchy → ACR → FMEA → energise.
