Here are pros and cons of the hub and spoke network model as compared to point-to-point:
http://en.wikipedia.org/wiki/Hub_and_spoke
Analysis of the model
The hub-and-spoke model is most frequently compared to the point-to-point transit model.
[edit] Benefits
* For a network of n nodes, only n - 1 routes are necessary to connect all nodes; that is, the upper bound is n - 1, and the complexity is O(n). This compares favorably to the (n(n - 1))/2 routes, or O(n2), that would be required to connect each node to every other node in a point-to-point network.
* The small number of routes generally leads to more efficient use of transportation resources. For example, aircraft are more likely to fly at full capacity, and can often fly routes more than once a day.
* Complicated operations, such as package sorting and accounting, can be carried out at the hub, rather than at every node.
* Spokes are simple, and new ones can be created easily.
* Customers may find the network more intuitive. Scheduling is convenient for them since there are few routes, with frequent service.
[edit] Drawbacks
* Because the model is centralized, day-to-day operations may be relatively inflexible. Changes at the hub, or even in a single route, could have unexpected consequences throughout the network. It may be difficult or impossible to handle occasional periods of high demand between two spokes.
* Route scheduling is complicated for the network operator. Scarce resources must be used carefully to avoid starving the hub. Careful traffic analysis and precise timing are required to keep the hub operating efficiently.
* The hub constitutes a bottleneck in the network. Total cargo capacity of the network is limited by the hub's capacity. Delays at the hub (caused, for example, by bad weather conditions) can result in delays throughout the network. Delays at a spoke (from mechanical problems with an airplane, for example) can also affect the network.
* Cargo must pass through the hub before reaching its destination, requiring longer journeys than direct point-to-point trips. This is often desirable for freight, which can benefit from sorting and consolidating operations at the hub, but not for time-critical cargo and passengers.