Andrew Johnston: Architecture and Consultancy Services

Case Study - Integration Architecture Development for National Grid Plc (2002 – 2012)


Development and evolution of a powerful and flexible enterprise integration architecture

Key Outcomes

Delivery of a flexible integration architecture which has delivered continuous business value as well as significant reduction in cost and complexity for several major system upgrades

Key Challenges

Wide range of systems to be integrated. Multi-party delivery environment. Continuous pressure to “shortcut” good design

Key Technologies

SeeBeyond, BizTalk and JCAPS integration, JMS, MSMQ, web service integration, XML, XSD, canonical data modelling


In late 2002, working with external consultants and the business, I articulated a new vision for the systems supporting Nation Grid Transmission's asset and work management. This was based around a central asset repository, with a document management system, a field force solution, and a comprehensive data warehouse with Business Intelligence tools, all integrated by a shared EAI backbone.

In subsequent years I acted as National Grid’s lead architect as this vision was progressively implemented, providing guidance and supervision to internal and external service and solution providers, maintaining a “hands on” approach.

I was actively involved in the design of the integration architecture. In order to provide maximum flexibility and isolate different systems from the complexities of one another we developed a scheme based around a canonical “common message model”, which has proven very capable particularly during a number of subsequent major system replacements. When the core asset management system was upgraded and restructured in 2007-9 we avoided any downstream impact on the field force, GIS, document management or data warehouse systems. Subsequently a number of other systems have been integrated, but it has frequently been possible to re-use existing flows, minimising the costs of new integration development.

I personally invented the solutions to a number of key problems, including a mechanism to track asset changes by comparing messages passing through the integration layer, and a rule-based “transformation engine” which transforms between the common message model and a very complex proprietary model doing away with a very large number of complex hand-coded transformations.

The benefits of the canonical integration architecture formed the subject of a paper I presented at the 2011 Enterprise Architecture Conference in London.

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