Calendar age matters through the mechanisms that make age consequential. Worn machinery and a declining hull create the immediate engineering problem, while upgradeability, suitability for the mission, and crew requirements test whether the repaired ship would remain useful. None of those factors can be judged in isolation because a structurally viable ship may still be too costly to adapt or crew. Together they form a replacement framework that avoids treating retirement as an automatic date on a planning chart.
Notable Point · 9:51-10:28
The core tests for replacing a class
Use this decision framework: component wear, hull life, upgradeability, mission suitability, and crew needs all bear on whether a class should stay or go.