System architects get new tool for their EA efforts

UML Version 2.0 provides greater flexibility and fluency in blending business and technical models

The most recent version of the Unified Modeling Language, which IT managers and enterprise architects use to model applications, data structures and business processes, will allow agencies to tie together system models more easily, even blend the business and technical parts of their EAs.

'UML Version 2 is a more exact specification, one that enables you to do systems-level modeling better,' said Lou Varveris, UML product manager for architecture and modeling software developer Popkin Software Inc. of New York.

The ABCs of UML

The Object Management Group, a nonprofit industry consortium that oversees UML, was to meet Jan. 30 to Feb. 4 to ratify version 2.0, said Jon Siegel, vice president of technology transfer for OMG. The move makes UML ready for modeling vendors to incorporate into their products.

True to its name, UML 2.0 offers the ability to unify a number of different modeling languages. The new version of UML 'is much more structured and formalized than [earlier versions], which didn't hang together as well,' said Einar Dehli, Metis product manager for Troux Technologies Inc. of Austin, Texas. (Troux acquired Computas Technology Inc. and its Metis line of modeling software last month.)

Users deploy UML to visually illustrate how different components within a system relate to one another, either by direct notation or through modeling software. Although first designed for software engineering, UML has been increasingly deployed by agencies to help map out large projects and systems.

UML is particularly well suited for modeling certain aspects of the Federal Enterprise Architecture Framework, most notably elements within the technical and data reference models, said Bob Daniel, senior solutions consultant for Troux.

For novices, however, UML can be difficult to master. It's easy to misunderstand the meanings of various UML elements, Dehli said. As a result, the General Services Administration, for instance, has backed away from using UML.

'We could produce UML diagrams from this Model-Driven Architecture repository we have, but we've stayed away from UML because it is too complex for the business people,' said Chris Fornecker, GSA's chief technical officer. Model-Driven Architecture is a standardized OMG process for developing new systems. 'We prefer to use notations more like what you see in [Microsoft] Visio or a swim lane diagram.'

While simplifying work for the end user, these kinds of specialized notations cannot be easily translated into other types of notations. As a result, agencies using multiple modeling languages may have difficulty reconciling various system views with one another.

'You look at one diagram and then look at another, they are not consistent. You have no way of seeing the discrepancies because they don't fit together underneath,' Dehli said.

Modeling application vendors want to be able to offer customers the ability to switch among multiple diagrams in such a way that all the diagrams they use are consistent with one another, even if they include different notations.

In government, such functionality would allow agencies to tie their IT project models directly to their enterprise architectures. It would also streamline the process of specifying system attributes to a contractor. A program manager can design a high-level diagram of a system, then pass the model file to a contractor, which can use the diagram to generate code. Likewise, the contractor can return a working technical diagram to the agency.

'What we didn't have before was the ability for a contractor to ship over a file that the government could tie to their enterprise architecture model,' Daniel said.

No empty nest

Although the newest version of UML may still be somewhat complicated, it offers hooks for working with various other modeling languages, according to Richard Soley, chairman and CEO of the OMG. It also provides additional specifications, called nested classifiers, that can define the relationships among different UML models, thereby making UML technology itself much more flexible.

'UML 2.0 can model at very many levels of abstraction, from extremely high architectural or business model view, zooming in to an extremely detailed view,' Siegel said. 'The high-level model can contain the information of the detailed models.'

Siegel said the specification was written primarily for modeling tool vendors, which can incorporate the updates into their own products. Jan Popkin, founder and CEO of Popkin Software, said he expects to see version 2.0 in the company's widely adopted Systems Architect product by mid-2005. Troux Technologies has already used a draft of UML 2.0 to generate a UML-based template for the Defense Department's Architectural Framework. Defense agencies use the DoDAF to help diagram how their individual systems will interoperate on a technical level.

Users don't deal directly with UML in the company's Metis modeling software, Dehli said. Instead, the software uses the standard to translate information between diagrams. Troux is also developing the ability for its Metis software to link different types of UML files into a single enterprise architecture-based environment.

Ultimately, what UML 2.0 can offer depends on how well the software vendors and agencies make use of the new specification.

'There are a lot of very smart people who worked on UML,' Popkin said. 'But the benefit is not in the technical specification, but in the way people apply UML.'

GCN senior writer Jason Miller contributed to this story.

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