The Book

Practical Data Migration

by Johny Morris - published by BCS, The Chartered Institute for IT

The primary data migration text since 2006. Thousands of copies sold worldwide. Now in its third edition, updated for modern technology and supply-side maturation.

Practical Data Migration book cover

Written for two audiences

Every data migration involves executives who must govern it and practitioners who must deliver it. PDM is written for both - deliberately, and in different registers.

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Executives

You are sponsoring the programme and signing off on cutover and the retirement of legacy systems. You may be a technologist or have no technical background at all - either way, PDM gives you the controls, the vocabulary, and the questions you need to govern a data migration with confidence.

  • Understand why migrations fail - and the perverse incentives that cause it
  • Know what a well-managed project looks like at every stage
  • Budget and resource a data migration accurately
  • Write supplier contracts that protect all parties
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Practitioners

You are the technologist facing a data migration project - perhaps for the first time, perhaps not. Either way, PDM gives you the full methodology: every module, every tool, every technique, and the reasoning behind each one.

  • Work through the full PDM process step by step
  • Structure business engagement so it actually works
  • Manage data quality in a way that is measurable and governable
  • Rescue a failing project - Section 3 covers this specifically

What's inside

17 chapters across three sections - from first principles through to the rescue of projects already in crisis.

Principles and Overview

For both executives and practitioners - read this first.

Ch. 1
Data Migration - What's All the Fuss?

Why migrations fail at scale. The Responsibility Gap. The seven success factors. Why the failure rate has not improved.

Ch. 2
The Golden Rules and Super Smart Tasks

The four non-negotiable principles of PDM, and how to structure business engagement so people become invested partners rather than passive recipients.

Ch. 3
PDMv3 Overview

The full end-to-end process - two workstreams, nine modules, the DMZ, and Release Management - in a single chapter.

Ch. 4
Migration Strategy and Governance

How to frame, govern, and plan a data migration project from day one. Policies, migration form, software selection, and resourcing.

The PDM Modules in Detail

For practitioners - the full working methodology.

Ch. 5
Introducing DQR

The Data Quality Rules process - the hub of all data quality decisions, the primary Super Smart Task, and the mechanism for business-led remediation.

Ch. 6
Demilitarised Zones

The contractual and operational boundary between client and supplier. How to define it, manage it, and use it to protect both parties.

Ch. 7
Metadata and Key Business Data Areas

The concepts of business items and KBDAs - how PDM measures and manages data at the level of granularity that business actually cares about.

Ch. 8
Key Data Stakeholder Management

Finding the people who know the data. Formal roles, engagement structures, and how to keep them involved throughout the project.

Ch. 9
Business Transformation Realisation

Capturing data owner requirements. Converting resistance into specification. Decommissioning certificates and acceptance criteria.

Ch. 10
Landscape Analysis

Systematic discovery of every legacy data store - including the unofficial spreadsheets and mini-databases that IT does not know about.

Ch. 11
Gap Analysis and Mapping

Mapping legacy data to target structures. Resolving semantic differences. Producing the mapping rules that drive ETL.

Ch. 12
Migration Design and Execution

ETL architecture, extract, transform, and load design. Building a data quality engine. Running the migration.

Ch. 13
Data Migration Testing

Continuous testing woven through every release. Test readiness criteria. How DQR metrics feed into test sign-off.

Ch. 14
Legacy Decommissioning

Retiring legacy systems properly. Logical and physical decommissioning. Archives, exit criteria, and decommissioning certificates.

Ch. 15
Agile, Waterfall and Blended

How PDM works with both agile and waterfall delivery models - and why the distinction matters less than practitioners think.

Ch. 16
Release and Configuration Management

Fortnightly release cycles, version control, and the governance structures that keep a migration on track.

Rescuing Failing Projects

For anyone whose project is already in trouble.

Ch. 17
Rescuing Failing Projects

A direct, practical guide to diagnosing what went wrong and applying PDM principles to get a migration back on track. Read the rest of the book first - this chapter uses concepts explained throughout.

Johny Morris

Johny Morris

Author, Practical Data Migration

About the author

Johny Morris spent over 20 years working for major systems integrators - including PwC, Logica CMG, and CSC - leading large-scale data migration programmes across utilities, financial services, healthcare, manufacturing, and the public sector.

PDM was not developed in a workshop or derived from theory. It was built from direct project experience - from what worked, what failed, and why. The third edition, PDMv3, reflects further evolution of the methodology in response to modern technology, the growing maturity of the data migration services market, and the ubiquity of Agile delivery practices.

Practical Data Migration has established itself as the primary text in the field since its first publication in 2006, with thousands of copies sold worldwide.

Get the book

Practical Data Migration is published by BCS, The Chartered Institute for IT (ISBN 978-1-78017-514-0), and is available in print and digital formats from the retailers below.

Prefer to learn by doing?

The PDM online course works through the full methodology using the DHGS case study - a realistic, end-to-end migration project with real-world complications. It's the book in practice.

View the Training Course