Critical infrastructure guide
Spare Capacity and Reserve Margin
Why critical systems need room to absorb peaks, outages and maintenance.
Systems note: infrastructure classifications, standards and responsibilities vary by country and operator. Use current local requirements for real decisions.
Why this matters
Why critical systems need room to absorb peaks, outages and maintenance.
Core system ideas
Operating every asset continuously at maximum load can leave little ability to absorb demand spikes or equipment loss.
Reserve capacity can exist in equipment, storage, staffing, alternate routes or contracted support.
Too much unused capacity is expensive, so planners balance resilience against lifecycle cost.
What to review
Useful reviews usually combine service criticality, dependencies, condition, capacity, maintenance, alternate arrangements, restoration time and clear ownership rather than relying on one isolated metric.