The decision-making process is a comprehensive analysis of several critical factors that go beyond just the initial cost.

1. Cost and Budget: overhead lines have a significantly lower initial installation cost, often being 5 to 10 times cheaper than underground systems. However, this must be weighed against the long-term operational and maintenance costs, as overhead lines are more prone to damage from external factors.

2. Reliability and Resilience: underground lines are inherently more reliable because they are protected from environmental factors like storms, wind, and lightning. This makes them the preferred choice for areas with frequent severe weather. Conversely, overhead lines are more vulnerable to these events, which can lead to more frequent outages.

3. Safety and Aesthetics: Underground lines are safer for the public because the energized conductors are buried, eliminating the risk of accidental contact or downed lines. They are also aesthetically pleasing, as they remove the visual clutter of poles and wires.

4. Maintenance and Repair: Overhead lines are easier to inspect and repair, as faults are often visible and accessible. This leads to quicker power restoration. A fault in an underground line, however, is much harder to locate and can require extensive excavation, resulting in a longer outage.