Two recent product moves by IBM and Microsoft throw a spotlight on the different approaches they're taking to modeling in software development. Both moves make it likely that modeling--the process of visually capturing what a system will do, and how--will take on a more important role in the way companies build systems.

IBM dominates the modeling field, based on its own experience and that of Rational Software, which it acquired in 2003. Rational set the standard for implementing Unified Modeling Language, a way to use symbols and syntax in models that can be shared across a broad suite of tools. The output of the model may then be used to generate code automatically.

IBM last week said it's making its Rational tools more industry specific, starting with the defense, aerospace, and automotive sectors. Its new Rational Test RealTime tool supports standards tied to avionics and defense software testing, as well as a standard for embedded software in cars and trucks. That should drive IBM's modeling approach even deeper into the enterprise.

BETTER LATE THAN NEVER

Microsoft, however, appears poised to capitalize on being a relative latecomer to modeling. Instead of adding modeling into the conventional steps of the development process, it plans with its Oslo strategy, announced this fall, to make modeling the first step in the process. Microsoft's approach will be simpler than the somewhat complex Unified Modeling Language of Rational, says Burley Kawasaki, Microsoft's director of product management.

The goal of Microsoft's approach is that a business analyst or skilled line-of-business manager could change the software model, and the underlying software services will change to reflect that. Microsoft VP Robert Wahbe has said this comes from the model capturing the business process--definitions, steps, outcomes--in metadata. Since the model is consulted at runtime, guiding what application elements are invoked to complete a business process, the metadata drives app execution. Change the metadata, change the process. This approach puts Microsoft "on a trajectory toward the deeper and more direct focus on business design," Forrester Research analyst Randy Heffner says in a report this month. The first elements of Microsoft's Oslo approach--such as an underlying, shared repository--will be in the next version of Visual Studio, which is years away.

IBM won't stand still as Microsoft labors to make its vision into a product. And IBM Rational modeling is already based on the one existing standard, Unified Modeling Language, while Microsoft will eschew UML in favor of its own modeling language.

Meanwhile, IBM's industry-specialized approach will help hook IBM tools into large, integrated systems used in these sectors. Expect health care, retail, and financial services to follow. But specialization alone won't be enough. In the long run, whichever modeling supplier best aligns development with companies' fast-changing business processes will come out ahead.