Federal Express Automated Regression Test System
FedEx Logistics Services provides third party warehousing and delivery services for its manufacturing and catalog house clients. Customers who call these companies for products actually talk to a FedEx person who takes their orders and enters them into a large Tandem order entry system. The order entry module is part of a comprehensive Tandem-based supply chain management system which controls order entry, shipping, invoicing, re-ordering, and payables.
FedEx periodically released new software upgrades for this system. The system had been in successful operation for many years, and the original developers were all gone. The maintenance staff, of necessity, was not as familiar with all of the intricacies of the system as the original developers, and the result was that FedEx was experiencing an unacceptable failure rate of their new releases.
They decided that their best solution was to implement an automated regression test system that would thoroughly test each release before it went into service. They retained The Sombers Group to design and build this system.
Relying on its extensive testing experience, Sombers built a system that was totally script driven. The scripts simulated terminal input and were read and interpreted by Sombers’ STAR product that sent messages to the Tandem system as if they were terminal-generated. Other utilities simulated inputs from other sources such as foreign IBM hosts.
All inputs and the resulting outputs – responses to the terminal inputs, responses from or queries to remote hosts, database updates, and spooled reports – were captured and compared to baseline results from the last test run. The only differences in the outputs should have been those due to changes in the release. The output data from a successful run became the baseline data for the next run.
Further information on this case study and the more general considerations that apply to automated regression testing may be found in our white paper entitled "ARTS – The Automated Regression Testing System."