Partial replacement or complete renewal?
Both approaches are valid; they simply do not address the same constraints.
|
Targeted replacement |
Complete renewal |
| Operational disruption |
Limited to the workstation concerned, often manageable during a quiet period. |
Longer, to be scheduled during a planned closure. |
| Works |
Reduced if the existing layout is retained. |
Opportunity to review the layout and traffic flow. |
| Line consistency |
Equipment of different ages and generations to be made to coexist. |
A homogeneous system, simplifying supervision and maintenance. |
| Investment |
Spread out over time, station by station. |
Concentrated, but with visibility spanning several years. |
In practice, many centres proceed in stages, starting with the most challenging section — often the brake tester, as it involves civil engineering works — and then gradually bringing the rest of the line up to standard.