Like O'Neill, IT managers at large corporations are increasingly concerned with tracking the continuous changes to their IT environments. They must be able to provide up-to-date information about their systems to internal and external auditors and quickly pinpoint problems in critical applications. And they can't to plan for the future growth of the IT infrastructure unless they have full knowledge of the existing applications and their interdependencies.

Given that most large organizations are supporting dozens -- sometimes hundreds -- of applications across global networks, it's nearly impossible to keep a real-time record of the IT enterprise. That's why application- discovery and -mapping technologies are gaining ground in corporate IT shops. Unlike network monitoring tools or mapping tools that focus on finding hardware, application mapping is primarily concerned with software components and their relationships, though the tools may also include hardware information as it pertains to an application.

For instance, application mapping can be very useful for IT architects who want an accurate inventory and diagram of the IT infrastructure so they can model future enhancements. Without a discovery capability, architects must manually input the information, which can result in errors as well as a static diagram that soon becomes outdated. Some architecture-modeling tools, such as those offered by Troux Technologies Inc. and Telelogic AB, are able to import architecture data from other vendors' mapping tools.

"We're seeing alliances between modeling tools and operational tools," says Gartner Inc. analyst Robert Handler. He notes that many organizations unwittingly have many redundant or just plain unnecessary applications.

"As much as 30 percent of IT budgets are spent on the support of applications that shouldn't have been approved in the first place," Handler says.