Architecture Description Markup Language

Architecture Description Markup

Language (ADML)

The new XML-based standard for IT architecture interoperability

ADML provides interoperability of architecture information, both between architecture tools and throughout the systems lifecycle.

1. What is ADML...?

The Architecture Description Markup Language (ADML) is an XML-based representation language for architecture. It was originally developed by the Micro-electronics and Computer technology Consortium (MCC) as part of MCC's Software and Systems Engineering Productivity (SSEP) project.

ADML is based on ACME, an architecture description language. The principal language design and tool development work for ACME has been undertaken by David Garlan, Bob Monroe, and Drew Kompanek at Carnegie Mellon University, and Dave Wile at USC's Information Sciences Institute. ADML adds to ACME a standardized representation (parsable by ordinary XML parsers), the ability to define links to objects outside the architecture (such as rationale, designs, components, etc.), straightforward ability to interface with commercial repositories, and transparent extensibility.

2. How Do I Use ADML? (And Why Should I Want to?)

This depends on your viewpoint: for example, whether you are an enterprise architect in an IT customer organization; a vendor of tools to support the IT architecture function; a vendor of other tools in the lifecycle that need access to architectural information; or a vendor of IT solutions that a customer organization is going to procure when implementing an IT architecture.

Enterprise architects do not use ADML directly, they benefit from ADML being adopted in the tools that they use to encode an architecture, because they can then import and export architecture constructs more easily between different architecture models, and among different architecture tools. ADML allows architects to create architectures more easily, with higher integrity, and faster.

For the architecture tools vendor, ADML will become the standard format used to encode the elements of an architecture. Since it is a standard, the tools vendor does not have to invent such a language, saving development costs. This also allows architecture information to flow more seamlessly between the various members of a family of tools that the vendor may have - e.g., from an architecture tool to a design tool, or form a business requirements capture tool to an architecture tool. The vendor can also import architecture information from any other vendor's tool that supports ADML, which makes such tools more open and flexible, and hence more attractive to potential customers.

Vendors of other tools is the systems lifecycle - for example, tools for requirements, modeling and simulation, performance evaluation, configuration management, etc. - will want to be able to import architectural information via ADML so that their tools can become useful parts of tomorrow's open toolset for IT architecture.

As with customer enterprise architects, IT solutions vendors do use ADML directly, they use tools that support ADML. ADML allows their product architects to create open product line architectures, enabling reuse of architecture artefacts both within the architecture process itself and downstream in the development process. Also for vendors who provide an architecture service offering (as many of the major solutions vendors do), the architecture service offering itself will be regarded as more open, because the architectures that are constructed on behalf of clients are usable by any tool that supports ADML.

3. How Does ADML Relate to UML?

UML is primarily a system design language, whereas ADML operates primarily at the level of enterprise architecture - "systems of systems". However, the distinction is not hard and fast, because the distinction between architecture and design is itself blurred. Large-scale individual systems often have an architecture, while the act of developing enterprise architecture often involves doing a first-cut high-level design in order to validate the architecture.

Another difference is that UML is a graphical language, whereas ADML is a markup notation, providing a textual (human-readable) notation for architecture description. XMI is being developed as an XML-based means of exchanging UML models, and we believe there is potential synergy here. We consider UML and ADML to be complementary, but there is currently a dialog ongoing between the ADML community within The Open Group and the UML community within OMG to help both sides understand this question better.

If you are interested in UML, download a presentation (PPT, PDF) that explains our view of the relationship with ADML.

4. Who Is Supporting ADML?

The concept of ADML is supported by large customers who have problems with architecture management. For example, the US Army has publicly stated (at the first Open Group Architecture Tools Symposium, Washington, October 1999) a need for ADML to allow sharing of architecture information between different vendors' tools.

However, in order for ADML to be fully embraced from a customer perspective, it must be embodied into COTS tools. In terms of implementations, ADML Version 1.0 is effectively a "trial-use" standard, which we are encouraging the industry to look at, with a view to implementing it and evolving it in line with customer requirements within The Open Group's Architecture Program.

We anticipate that customer pull for the benefits that ADML offers will persuade a significant number of COTS tools vendors to adopt ADML in the near future, and contribute to its further evolution.

5. Why Should Tools Vendors Care about ADML?

This is explained in summary above. If you are a tools vendor, download a presentation (PPT, PDF) that explains the business case in detail, and the roadmap that we envisage a tools vendor taking in the implementation of ADML.

6. How would Customers benefit from using ADML Enabled Tools?

Any organization implementing an enterprise-wide technical infrastructure for the support of mission-critical business applications, using open systems building blocks, will benefit from using tools that support ADML.

This standard for the description of architectural information makes possible the broad sharing of models, so that many present and future tools can manipulate, search, present, and store the model. Given the ongoing adoption of XML by industry, XML-based ADML models will be in a format that will not become orphaned. And a standard, open representation will decouple an enterprise's architectural models from vendors, and enable the models to remain useful despite the rapid change in software tools

7. How will ADML Evolve in the Future?

ADML Version 1 is the initial Version of the ADML standard, based on technology developed by the Micro-electronics and Computer technology Consortium (MCC). It is currently designed to facilitate the interchange of architecture models between different architecture tools.

We anticipate that tools vendors will want to participate in the evolution of ADML, and to this end The Open Group intends to provide a forum within The Open Group's Architecture Program, in which such vendors can work together with customer IT architects and major solutions vendors, to evolve ADML in line with the requirements of the industry at large.

We believe there are significant opportunities for further evolution of ADML. The Open Group's Architecture Program is intended to provide a forum in which that evolution can happen, with customer enterprise architects articulating their requirements for an industry standard for architecture definition and interchange, and tools vendors providing feedback on implementation.

In particular, we believe that ADML offers opportunities for evolution in a number of complementary ways:

As a standard for architecture based product line engineering, which is the focus that MCC had in originally developing the ADML technology.
As the basis for a new class of tools that properly support the architecture function.
- Currently architects wanting to use robust tools for architecture description have to resort either to simple drawing and presentation tools, or to complex tools aimed primarily at design and development and leading directly to code generation. Many of the latter tools typically support UML. They are excellent for their primary purpose of design/development, but the adequacy of UML for properly supporting architecture semantics has been widely questioned in technical journals in recent years.
As a standard means of interchanging architectural semantics, between architecture tools, and between architecture tools and tools used at other stages of the life-cycle, including the design/development tools mentioned above.
- We envisage ADML being the means of communicating key architecture semantics, both between architecture tools, and between those tools and tools used at other phases of the systems life-cycle: for business process modelling, requirements and rationale capture, system design, testing, etc.
As the basis of a "building blocks description language", capable of encoding architectural building blocks in a tool-independent format.
- As part of its wider vision, The Open Group aims to set up a "Building Blocks Information Base" - a database of building block definitions importable by any tool supporting the ADML standard. This will be analogous to our existing Standards Information Base at: http://www.opengroup.org/sib.htm
- A draft business scenario of how the Building Blocks Information Base would operate is available (HTML; PDF; Word)

In summary, ADML represents an excellent basis on which tools vendors can implement tools capable of supporting the needs of the enterprise architect now and into the future.

8. Where can I find More Information on ADML?

The ADML Documentation on the open Group Publications web server
The ADML Document Type Definition (DTD)
The ADML White Paper - explaining these concepts in greater detail.
Other web sites of interest:
- http://www.cs.cmu.edu/~acme/pub/xAcme/ - Carnegie-Mellon University's work on xAcme, CMU's own XML instantiation of the Acme system, on which ADML was based, using XML schemas.
- http://www.rdg.ac.uk/~sis99scc/admiral/ - Reading University's work with ADML and TOGAF - provides various ADML-related links

9. What Should I Do Next?

Attend the next Open Group Conference to find out more about ADML and help shape the program for its further evolution.
Contact The Open Group to discuss your interest, or raise any queries:
- mailto:j.spencer@opengroup.org