Andrew Johnston: Architecture and Consultancy Services

Case Study - Data Centre Migration for IBM / National Grid Plc (2012 – 2013)


Migration of National Grid’s business systems to a new “private cloud” at CSC data centres

Key Outcomes

Successful migration of the majority of systems, leading to reduced IS costs and a better alignment with the new regulatory funding regime. Modernisation or rationalisation of several legacy systems.

Key Challenges

Complex multi-party supplier structure. Aged legacy systems with unsupported technologies and limited documentation / knowledge

Key Technologies

Various Windows and Unix server OSs and hosting arrangements. Virtualisation and physical migration. Wide variety of application and client technologies. Networking including firewalls and extranet.


National Grid contracted with CSC to re-host the majority of their systems in new CSC data centres. I worked as the lead architect for the IBM team supporting that programme, planning and assuring the migrations from an application perspective. This required building a comprehensive understanding of around 50 complex and legacy applications to identify an appropriate migration approach, required remediation work and appropriate testing for every application. I also had to ensure that the preparations being made by IBM, CSC, networking partners and third party application vendors would provide for a “joined up” and low risk migration of each application in the IBM support portfolio.

It became apparent early on in the programme that there were few established processes and templates suitable to the National Grid situation, and I led a multi-partner exercise to progressively develop a suite of guidelines, documents and processes which could be repeatably applied by various teams to develop the required understanding for each application in turn.

During the actual migrations I took an active coordinating and troubleshooting role, on several occasions identifying the source of issues and their likely resolution.


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