National Weather Service: Building a Better Forecast Model: Page 4 of 6

Timing was everything. The latest simulation tool, OPNET Technologies' Modeler, was a mature product and the NWS had a clear business case for network simulation: NWS was in the process of developing its new National Digital Forecasting Database (NDFD), and the NWS IT group needed a way to measure the impact the new graphics-heavy database would have on its infrastructure--the WAN, servers and applications. "There were a lot of unknowns and a lot of expense associated with that," Chambers says. "So rather than just throwing money at these things, we were trying to find a way to manage our fiscal resources while doing some capacity planning and systems engineering. We had less money, so we had to spend it more intelligently."

Although network simulation seemed the obvious choice, Chambers and his supervisor had to do some prodding and cajoling to sell the concept, especially with the skeptics who had experience with previous modeling tools.

"The folks who had bad experiences with other modeling efforts were not an easy sell," Chambers says. In all, it took about 18 months to get everyone on board with ACNM. What eventually sold the most jaded cynics was the prototype Chambers' team built. "ACNM answered all questions with a high degree of accuracy," he notes. Its test data on server capacity and other readings rang true. "The tool's output was validated with real-world data," Chambers says.

In today's cloudier IT budget climate, however, a project like ACNM probably wouldn't fly. Like other government agencies, NWS is facing millions of dollars in budget cuts. A simulation tool would be considered nice to have but not essential, Chambers says. It's mainly the workstations and server upgrades that make the budget these days. "You're not going to get money for this model--it's just not there now," he says.

Randy Chambers -- Operational Manager, National weather service's; Network control facility, silver spring, MD.