Making sure it's 'service as usual'

AT&T is a global telecommunications company providing a variety of services from long-distance-voice to data, video, wireless, satellite, and Internet services. AT&T faced a problem of preventing failures in the carrier's network and preparing a rapid response should failures occur. For AT&T to re-route traffic quickly in the event of a network failure, the network had to contain sufficient restoration capacity to carry the displaced demand. The problem was critical because failures of service directly affect the company's core service and erode customer loyalty. Solving it demanded operational research expertise because the problem was system-wide and OR had the strong capability to consider the numerous parameters involved.

An AT&T team of OR experts, network planners, and managers developed a method for determining the appropriate amount and location of restoration capacity required to restore the demand during any single link failure. The approach centered on minimising the cost of the restoration network and generating new restoration paths.

In about 10 months, the team converted the methodology into a tool that optimises the allocation of restoration capacity. This tool was then extended to plan for the recovery of a switching-centre disaster and to re-optimise the entire restoration network. The project has contributed to AT&T's achieving high-quality service while saving valuable resources, resulting in hundreds of millions of dollars in cost savings and increased revenues.