If IBM closes its expected $2.1 billion acquisition of Rational Software Corp. this quarter, the vendor will be able to complement its WebSphere Studio suite of Java software-development tools with technology that lets developers and IT managers draw detailed diagrams of software projects that contain technical information about an application's design and function. If the acquisition lives up to its promise, development teams will gain flexibility to transform those models into executable code, saving time and boosting quality.

"We've reduced the amount of back-and-forth interaction between our designers, developers, and quality-assurance staff when we bring UML tools into play early on," says Andy George, VP of research and development at GERS Retail Systems, a vendor of point-of-sale and E-commerce software for companies such as Nextel and Black & Decker. GERS uses Rational Rose, Rational Software's widely used UML tool, to draw detailed scenarios of how cashiers and customers might interact and to store software components and functions related to those interactions so they can be reused. That's especially important since GERS often designs software in collaboration with customers.

Borland Software Corp. this month plans to close its $185 million acquisition of TogetherSoft, whose tools compete with Rational's UML tools. The TogetherSoft deal plus two other acquisitions last fall complement Borland's strength in programming languages and visual-development tools.

IBM and Borland want to become suppliers of development life-cycle management tools that help customers quickly move from understanding a software project's requirements to visually mapping the underlying business process, modeling the application, writing code, and testing the finished product. "Building secure, distributed systems isn't the forté of the average programmer," says Grady Booch, chief scientist at Rational and one of the developers of UML.

The deals also could make IBM and Borland tougher competitors against Microsoft in the market for software-development tools, sales of which market research firm IDC estimates to be $9 billion annually. Sales of modeling tools grew 3.5% in 2002 to about $619 million, after declining 12.4% in 2001, IDC says. By 2006, sales could reach $1.1 billion. For that projection to come true, UML, which is notoriously difficult to use, must become accessible to more developers so companies can deploy the tools to manage reusable code, not just draw up specs. "The key is extracting content and being able to reuse it, in addition to drawing a picture," says Duncan Dwelle, chief information technology officer at payroll processing company Accuchex Corp. and a consultant on modeling tools.

Buying Rational would give IBM control of an important Microsoft partner. Microsoft licenses Rational technology for the Visual Modeler feature of its Visual Studio suite and refers customers to Rational for more sophisticated jobs. As Microsoft promotes its new object-oriented .Net class of software-development languages, tools that help customers understand applications' object models could become more important. Microsoft competitor Oracle last year bought modeling tools from WebGain Inc. for inclusion in its JDeveloper suite. IBM and Rational say they'll continue to ship versions of Rational's software that work with .Net, and IBM says it hopes to sell Rational's products to Microsoft-centric IT shops. Customers are skeptical. "I doubt they'll be supporting Microsoft products as much as they did in the past," says Patrick Heath, director of engineering at systems integrator Molecular Inc.

Microsoft's own scaled-down modeling tools are growing in popularity. Thirty-six percent of IT managers cite Microsoft's Visio technical-drawing software as their preferred modeling tool, up from 26% last year, according to a survey of managers at 400 large companies by market researcher Evans Data. Microsoft's tools are cheaper than offerings from vendors such as Computer Associates, Embarcadero Technologies, Rational, and TogetherSoft. Microsoft bundles a version of Visio that generates UML code with its Visual Studio .Net Enterprise Architect product, which lists for $2,500 per seat. Seats of Rational Rose can cost $10,000 to $15,000. Still, it's not a mass-market product. Microsoft lead product manager Dan Hay estimates less than 10% of professional developers use modeling tools. "Learning the UML isn't an easy proposition," he says.

If IBM's plan pans out, though, more rank-and-file developers could use Rational's Rose and XDE software in conjunction with IBM's WebSphere development tools to quickly build on-demand applications that call Web services and computing resources remotely -- and help developers understand how changes to one part of an application ripple through systems.

UML tools also can generate business logic that's a starting point for coders. That concept is key to IBM's and Borland's time-to-market arguments. It may be harder to get results in practice. Molecular's 30 software engineers use Rational Rose to plot the object models of apps they design for customers such as Deutsche Bank and Staples. But programmers have given up trying to automatically generate code from the models, Molecular's Heath says.

Borland, too, is pushing tighter links between models and visual-development environments. Last fall, Borland bought Starbase Corp., a maker of software for managing source code, and BoldSoft, a Swedish maker of modeling technology for Windows. Both will come to bear on development tools Borland plans to release this year for Microsoft's .Net framework and that compete with Visual Studio.

Not everyone is sold on the vision. "I would be deliriously happy if that were true in large numbers," says Accuchex's Dwelle. But "it's a hard sell to get people who are charged with writing code to write documentation. And a model is a very abstract documentation."