On May 18, 1998, an estimated 80 to 90 percent of the pagers in the United States went out of service when the $250-million Galaxy IV satellite rolled out of control and lost track of the Earth. PanAmSat, the Greenwich, Connecticut company that operates Galaxy IV, switched communications to another satellite, but not before pager, radio, television, and credit-card transmissions were disrupted for up to two days in some areas of the country. The net economic cost was astronomical.

When America Online (AOL) went to a flat-fee, unlimited-access rate, this Internet service provider (ISP) lost thousands of subscribers and offered refunds to countless others. The change had increased network traffic so much that callers to AOL had difficulty making connections, especially during peak periods. The network congestion also made it harder for non–AOL callers to make connections, because they were using some of the same telecommunications infrastructure.

These real-world examples point to the growing challenges involved in managing service availability and service levels in today’s explosive and rapidly changing communications environment. They represent worst-case scenarios not only for end-user customers, but also for those organizations responsible for managing service levels and ensuring quality of service (QoS).