Traditional protection planning often begins with a list of assets: a building, communications node, substation or control center. A systems approach starts elsewhere — with the function. For example: maintain power for critical equipment, transmit a message, supply water, make a decision or deliver a resource.
Why this changes protection architecture
If a function can be performed through several independent paths, the loss of one physical carrier does not necessarily stop the system. Attention shifts to redundancy, alternative routes, reserves, distributed governance and procedures for moving into degraded operation.
This does not make physical protection irrelevant. It helps identify where hardening is truly critical and where an alternative channel or rapid recovery capability provides greater resilience.
Practical question
For every system, it is useful to define the minimum acceptable level of function, autonomy duration, critical dependencies and recovery sequence. This becomes the basis for resilience assessment.