FedEx wanted to create a speech-recognition system that would help people in its U.S. market determine how much it would cost to send packages. They knew that people who call them on the phone (that is, don't use the Web interface or a rate book) don't ship frequently. So this application had to work for people with little FedEx shipping experience.
Most people ship packages using the standard FedEx envelopes and boxes. But some use their own packaging. FedEx needed to obtain the dimensions of these nonstandard containers from the callers to ensure that they were not too large to send via the FedEx standard service.