APPLICATION: Corporate Tax Module (CTM) -- Taxes are inevitable -- every incredibly numerous type of local, state and federal taxes. Information systems (I/S) bosses at telecommunications giants like AT&T Corp. face a constant challenge to properly calculate the right tax type and amount. AT&T must apply sales, telecommunications and use taxes for approximately 90% of its revenue stream.

The task of computing the proper taxes is made more difficult as governing bodies change tax laws forcing I/S organizations to update tax business rules. For years, AT&T utilized the Corporate Tax Module (CTM) system, which required that software modifications be mailed on disk to the various AT&T sites around the country. At these sites, I/S personnel manually upgraded systems, which Craig Swanson, a manager in the AT&T CFO tax department, said was a tedious and time consuming process. Complicating the issue was the number of different platforms on which each of the billing systems operate.

The original CTM system, built in the early 1980s, was written in MVS Cobol to support residential and business billing systems. The emergence of Windows through the early 1990s prompted AT&T's Corporate Tax Team (CTT) to investigate rewriting the mainframe system and its not-so-user friendly 3270 green screens for a more user-friendly system that supported Windows GUI clients.

The team decided to move to Unix-based billers on the back end that connected to Windows clients on the front-end -- a system they called CTTCALC. The company used the Cobol for Unix tools from Micro Focus Inc., Palo Alto, Calif., to build the new billers. But with the first implementation of a Unix-based biller, Swanson and company realized that Micro Focus' Cobol for Unix did not support all the flavors of Unix that AT&T was using.

While this new system proved popular and use of non-mainframe billers "mushroomed," too many code compromises were being made to write code to the various Unix flavors, plus there was the issue of mailing disks upgrades to all the necessary sites whenever there was a change in logic.

Recently, AT&T noticed the potential of using its Intranet to distribute the biller information to the various customer service representatives throughout the country. The system was completely rewritten using object-oriented technology that allowed for the separation of business rules from the presentation. AT&T used the Rose modeling tool from Rational Software Corp., Cupertino, Calif., and C++ running on a Sun Microsystems SparcCenter 2000 to rebuild the entire biller system.

"The biggest thing was to get the taxing system into the various platforms much quicker that in the past," Swanson said. "The client/server aspect gives us the ability to port to thin clients."

Approximately a dozen programmers came together to build the new system that operates over the corporate Intranet and uses thin clients for the Sun Solaris, Windows NT and HP-UX front-end systems.

- Jason J. Meserve