Accelerating The Reuse of Existing Legacy Systems

Whether you refer to your project as Portals, EAI, BPM, Basel II, SOA, integration, porting to a new platform, migration, transformation, evolution, downsizing, off-loading or architecture consolidation – the common theme is building on your existing investments and making the most of the application services, data and development processes that you have.

A wide range of approaches have been tried over the years to “making the most of your existing investments”. A new idea that shows a lot of promise for accelerating the reuse of existing legacy systems, and that is beginning to gain wider recognition, is “Architecture-Driven Modernization” (ADM) from the Object Management Group (OMG).

OMG Architecture-Driven Modernization

In 2003 a number of interested OMG members, (including Delta Software Technology) came together at the OMG Technical Meeting in Paris, France to form a new working group to apply the concepts, practices and standards of Model-Driven Architecture (MDA) to create interoperability standards for modernization tools.

MDA is a top-down model-driven process for developing new systems, whereas Architecture-Driven Modernization (ADM) is a bottom-up approach to accelerate the reuse of existing legacy systems.

ADM incorporates the bottom-up extraction of architectural models from the existing software implementation, followed by their top-down reuse in MDA processes. Further, ADM describes in detail the individual scenarios for the modernization of legacy systems, giving a direct connection to usage in the real-world.

ADM can be thought of as “closing the gap” between the different methodologies and tools available for old and new systems.

Since the initial meeting in Paris ADM has quickly established itself and become one of the most active OMG areas. ADM has now achieved the status of a formal OMG Task Force and the first two standards are already subject to the final voting process.

Delta is closely involved with the modernization work being performed by the ADM Task Force (ADMTF). Rüdiger Schilling, Delta’s co-founder and CTO, will be attending the next OMG Technical Meeting in Atlanta, USA in mid-September to continue work on the ADM standards.

OMG Defines Modernization

The ADMTF defines modernization as being the process of understanding and evolving existing software assets, whereby modernization can be decomposed into three basic activities:

• Assessment – Analysis and exposure of system and business artefacts, architectures, data and process flows, system structure and behaviour.
• Stabilization and Standardization – Tasks that structure, rationalize, realign, modularize and otherwise refactor existing systems.
• Transformation – Extraction of data definitions, data and business rules, along with the reuse of existing system artefacts in the redesign of the target architectures.

The ADMTF is driven by vendor and end-user organisations that want to extract meta-data from existing software environments and then to share this information across a broad range of modernization tools. To do this effectively requires defined and accepted open standards.

The OMG strives to closely relate their standards work to business practice. Therefore, the ADMTF is taking a pragmatic approach, basing their work around real-world scenarios based on typical modernization projects.

Modernization Scenarios

In order to ensure that ADM standards evolve to support various users, customers, strategies and projects, the ADMTF has defined a range of modernization scenarios that the future ADM standards may facilitate:

• Application Portfolio Management
• Application Improvement
• Language-to-Language Conversion
• Platform Migration
• Non-Invasive Application Integration
• Services Oriented Architecture Transformation
• Data Architecture Migration
• Application & Data Architecture Consolidation
• Data Warehouse Deployment
• Application Package Selection & Deployment
• Reusable Software Assets and Component Reuse
• Model-Driven Architecture Transformation

Defining such scenarios is useful as experience shows it is difficult for someone unfamiliar with modernization to envision all of its potential applications. For example, it may not be readily apparent that modernization can help leverage the refactoring of several applications to facilitate migration to services oriented architecture (SOA).

Modernization scenarios provide an excellent way of talking about the types of projects where modernization tools and techniques can be of value. This is an approach that Delta has been using for a while now with SCORE Adaptive Bridges for non-invasive integration. You will be seeing more about how Delta supports the individual OMG Modernization Scenarios in the near future.

OMG Architecture-Driven Modernization Tutorial

The ADMTF presented a comprehensive (109 slides!) tutorial on Architecture-Driven Modernization at the OMG Technical Meeting held in Athens, Greece in April 2005.

OMG Tutorial on Architecture-Driven Modernization

This tutorial introduces the concepts of ADM and then moves on to look in detail at the first two standards that are being defined by the ADMTF – Knowledge Discovery Meta-model (KDM) and Abstract Syntax Tree Meta-model (ASTM). The presentation is in Microsoft PowerPoint format and is in English.

 OMG Standards for ADM

The ADMTF has defined a multi-year roadmap consisting of seven inter-related standards to facilitate the interoperability of modernization tools. These standards cover the following broad areas:

• Knowledge Discovery
• Abstract Syntax Tree
• Analysis
• Metrics
• Visualization
• Refactoring
• Target Mapping & Transformation

The ADMTF has started with a Knowledge Discovery Meta-model (KDM) that defines a common view of application meta-data. Users of tools that support the KDM can then collect and integrate this information for a variety of platforms, languages, databases, interfaces and environments.

The KDM is based on the OMG Meta-Object Facility, a standard for the definition and usage of meta models that has been used by Delta in a number of products, including SCORE Adaptive Bridges. Delta’s transformation solutions based on AMELIO and SCORE Transformation Suite perform knowledge discovery of existing applications and we will be working to bring these into line with the evolving OMG ADM standards.

Further Information

If you would like to know more about building on your existing investments and how Delta can help you to make the most of your application services, data and development processes then please contact your local sales representative.