Interoperate or Evaporate
by Alan Kotok |

Object Modelers vs. the Angle-Brackets

Another apparent division emerged between Unified Modeling Language (UML) and XML practitioners. Early in the meeting, Richard Soley, chairman and CEO of OMG, discussed the group's Model Driven Architecture based largely on UML. Many standards groups have begun using UML as a tool to define business requirements and processes, independently of potential technical solutions. Soley said the the Model Driven Architecture's goals are not only interoperability but also software portability, the ability to reuse software assets across different platforms.

The portability issue is an important one to software developers but not a critical need of e-business standards, which focuses more on exchanging data in business documents, and one of the participants questioned Soley on whether the issue of portability fit the main (interoperability) topic of the meeting. Solely noted that protocols may exchange the documents but APIs need to manipulate documents. The portability issue affects APIs. He also made a distinction between data models, often the stuff of e-business standards groups, and object models. Data models, while perhaps sufficient for interoperability, do not address software portability.

UML advocates got an even sharper shock when one of the key developers of HR-XML spoke at length about the inability of UML to meet the needs of a large-scale human resources systems project undertaken by the U.S. Department of Defense. Enrique Kortright, of the U.S. Navy Space and Warfare Command's Information Technology Center, discussed how the initial modeling of the planned Defense Integrated Human Resources System (DIMHRS) ran into problems using UML. This project is a large, complex undertaking, eventually serving 3 to 4 million employees, with thousands of entry points and concurrent users, and exchanging data with finance, education, health care, retirement, and civilian personnel systems.

Kortright said the goal of modeling this system was to capture the business knowledge of human resource professionals, and like Bob Sutor of IBM, he had to evaluate the available standards against the needs of that project. However, he found UML limited in its ability to record complex business behavior. Based on this experience, he said UML was both too complex and too restrictive and forced the modelers to make decisions irrelevant to the overall goals of the project, such as classifying professional human resources knowledge between classes and attributes. Kortright also discovered that human resources experts could not understand the UML notation. The DIMHRS designers ended up using another graphical modeling language called Object Role Modeling, which like UML uses a graphical notation but is more expressive.

The DIMHRS experience provided a reference model on which HR-XML was based. While the model had some unique features, many of the underlying principles apply to most human resources systems, and HR-XML took advantage of this basic research on human resources functions. Chuck Allen later said that HR-XML used UML for its business process modeling, and that the DIMHRS experience with UML applied only to that business domain.

Taking the First Steps to Bridge the Divisions

The conference included a brainstorming and facilitation exercise, led by Gary O'Neall of PlaceWare, to identify impediments to collaboration and to agree on steps for overcoming them.

The first brainstorming generated a list of 42 items that the group boiled down to 13 factors, from which five emerged as the leading issues:

1. Roll your own : reluctance to give up turf, hidden agendas, and lack of trust among standards organizations

2. Differing scopes and processes: incompatible operating processes, varying scopes of standards, different origins and missions of standards groups

3. Lack of perspective: failure to see the need for multiple groups contributing to e-business standardization, tunnel vision/inability to see the big picture

4. Lack of awareness of other groups: lack of knowledge of the existence of other groups, as well as their goals, missions, activities; lack of time and energy to keep up with standards world, lack of basic technical understanding

5. Lack of common vocabularies,: both industry and natural languages, as well as lack of international outlook

Of these five issues, most participants said the first was the most serious, and the group discussed steps for dealing with the problem, but they focused on steps that involve working with current organizations, not starting other groups. The most productive steps included establishing formal liaisons between organizations (including the use of online tools), and sharing groups' missions, architectures, and scopes. Practical steps such as scheduling meetings in the same cities at about the same times would help make coordination that much easier.

Four of the sponsors, OASIS, OMG, HR-XML, and XBRL, agreed to hold a second meeting in this series, focusing on procurement, in June 2002. Karl Best of OASIS offered that group's XML.org registry as a host for an authoritative list of standards. Bob Hager of American National Standards Institute also described its standards registry and metadata exchange work with ISO.

A basic understanding coming from the meeting was the need for a multi-dimensional approach to e-business standards, which means that no one group could or should try to control the entire e-business standards landscape. In that spirit, Chuck Allen saved perhaps the most important announcement about standards convergence for the end of the meeting, when the number of participants had dwindled to about 20.

In that last session, Allen and Kim Bartkus of HR-XML discussed the Staffing Industry Data Exchange Standards (SIDES), some of which include processes not unlike those found in many other industries: request for quotations, orders, and invoices. Rather than writing their own specifications for these processes, HR-XML will deploy SIDES transactions as Open Applications Group (OAG) messages in order to take advantage of their several years worth of work on these kinds of business documents. OAG messages can be implemented either in ebXML or in Microsoft's BizTalk, which will give HR-XML a wide base of potential implementations.

This approach allows HR-XML to capture its business knowledge in an HR industry vocabulary, yet at the same time connect with more generic business messages and architectures, and thus provide a greater chance for interoperability with other vocabularies. Since most companies and organizations conduct at least some human resources functions, one can see how this approach will benefit a wide range of industries, which should be the whole reason for using XML in the first place.

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