About

The methodology behind the method

Practical Data Migration was built on two decades of project delivery - not in a workshop but on real programmes where the same failures kept happening for the same structural reasons.

Johny Morris

Author · Consultant · Data Migration Practitioner

Johny Morris has spent more than two decades at the sharp end of enterprise data migration. Before writing the book that would define the discipline, he led large-scale migration programmes at major systems integrators, PwC, Logica CMG, and CSC, across utilities, financial services, healthcare, manufacturing, and the public sector.

What he found, project after project, was that the same failures kept recurring. Not because of the technology. Not because of a lack of skill. But because of something structural: data migration was consistently framed as a technical problem when it was fundamentally a business problem. The Responsibility Gap - the no-man's land between IT and the business where data quality issues go to die - was not a personality clash. It was a structural inevitability of how projects were designed.

PDM was built to close that gap. In 2006, Morris published the first edition of Practical Data Migration through the British Computer Society. It was the first non-proprietary, vendor-neutral methodology for enterprise data migration - and quickly became a widely used reference.

A methodology built over three editions

Practical Data Migration has evolved continuously since 2006, each edition reflecting how the industry has matured, not a change in core principles.

2006
Practical Data Migration first edition cover

PDMv1 - the first edition

Published by the British Computer Society, PDMv1 introduced the four Golden Rules, the Responsibility Gap, and the core module structure that guides practitioners from landscape analysis through to decommissioning. It was the first vendor-neutral methodology for enterprise data migration.

2012
Practical Data Migration second edition cover

PDMv2 - refined and extended

Six years of additional practice and the growing maturity of the data migration market shaped the second edition. The Golden Rules remained unchanged. The module guidance was refined with richer real-world examples and sharper guidance on stakeholder management and governance.

2024
Practical Data Migration third edition cover

PDMv3 - the current standard

The third edition reflects a decade of technological change - cloud migration, Agile working, the explosion of migration tooling - and the further maturation of the services market. New chapters address how PDM modules operate as service objects within Agile programmes. The four Golden Rules have not moved an inch.

Data Migration Matters

Alongside the book, Johny Morris has been a driving force behind Data Migration Matters - the only European conference exclusively devoted to data migration. Running for over a decade, it has brought together practitioners, executives, and researchers to share experience, debate emerging practice, and build the community around a discipline that the broader industry has long underserved.

The conference reflects the same conviction that underpins PDM: data migration is a distinct discipline, not a subset of something else, and it deserves its own body of knowledge, its own community, and its own professional standards.

18+
years of practice behind PDMv3
3
editions - principles unchanged throughout
1
European conference for the discipline

Published by the British Computer Society

Practical Data Migration is published by BCS, The Chartered Institute for IT - the professional body for computing in the UK. BCS publishes peer-reviewed practitioner and academic computing texts; inclusion in that catalogue reflects the rigour and independence of the methodology.

The book is available from the BCS bookshop, Amazon, and Waterstones. ISBN: 978-1-78017-514-0.

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Learn the methodology

The PDM online course on Hopp Academy takes you through all nine modules with the DHGS case study running throughout.

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Join the community

PDM-certified practitioners are invited to join the community of practitioners - sharing experience and promoting their expertise.

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Read the book

The third edition covers all nine modules in full depth, with guidance for both practitioners and executives.

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