Databases Reference
In-Depth Information
shopping, the number of parcels has increased significantly. Amazon and eBay deliveries
now account for more than half the parcels routed and delivered by Global Post each
day.
With parcel volumes continuing to grow, and facing strong competition from other
courier services, Global Post has begun a large change program to upgrade all aspects
of its parcel network, including buildings, equipment, systems, and processes.
One of the most important and time-critical components in the parcel network is the
route calculation engine. Between one and three thousand parcels enter the network
each second. As parcels enter the network they are mechanically sorted according to
their destination. To maintain a steady flow during this process, the engine must cal‐
culate a parcel's route before it reaches a point where the sorting equipment has to make
a choice, which happens only seconds after the parcel has entered the network—hence
the strict time requirements on the engine.
Not only must the engine route parcels in milliseconds, but it must do so according to
the routes scheduled for a particular period. Parcel routes change throughout the year,
with more trucks, delivery people, and collections over the Christmas period than dur‐
ing the summer, for example. The engine must, therefore, apply its calculations using
only those routes that are available for a particular period.
On top of accommodating different routes and levels of parcel traffic, the new parcel
network must also allow for significant change and evolution. The platform that Global
Post develops today will form the business-critical basis of its operations for the next
10 years or more. During that time, the company anticipates large portions of the net‐
work—including equipment, premises, and transport routes—will change to match
changes in the business environment. The data model underlying the route calculation
engine must, therefore, allow for rapid and significant schema evolution.
Global Post data model
Figure 5-11
shows a simple example of the Global Post parcel network. The network
comprises parcel centers, which are connected to delivery bases, each of which covers
several delivery areas; these delivery areas, in turn, are subdivided into delivery segments
covering many delivery units. There are around 25 national parcel centers and roughly
2 million delivery units (corresponding to postal or zip codes).
