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BJSS Expertise: Data Migration

Data migration is a critical component of many IT projects, yet despite its importance to the overall success of a project it is often overlooked.

BJSS has track record in the successful management and implementation of large-scale data migration projects under the most challenging conditions. For both public and private sector clients, BJSS has provided secure migration solutions for large data volumes often spanning different locations, disparate storage technologies and storage paradigms.

BJSS Data Migration Expertise


Successful large-scale data migrations are underpinned by a clear strategy, informed by expert analysis of a range of critical factors


Data migration should always be undertaken early and continuously using an approach tailored to the data volumes, transformation complexity and cutover time targets.


Implementation method depends upon the specifics of the migration and the nature of the source and target systems, but all present a number of common challenges:
  • Support for partial processing of source data
  • Parallelisation
  • Progress and error monitoring
  • Automation


The criticality of data migration process means that any quality issues are likely to have a disproportionately high impact on the success of the project. BJSS has developed a range of techniques for ensuring that data integrity is maintained – a multi-layered approach mitigates the risk of data integrity issues being overlooked by any single technique

Successful large-scale Data Migrations begin with a clear strategy.

BJSS has identified 10 critical factors determining the approach required. This White Paper is for IT decision makers within CIO/ CTO functions, delivery programmes and Operations. It outlines the important considerations for a Data Migration project, what the typical pitfalls are based on BJSS’ extensive experience, and how to overcome them.

“BJSS quickly gained our confidence and despite changes in scope, met all key delivery dates and delivered within budget. The HES Transition Project has delivered significant reduction in annual running costs.” Dave Andelin, Programme Manager, NHS Information Centre 

Replacing the NHS Hospital Episodes Statistics (HES) system, BJSS developed, tested and deployed a suite of data migration tools to migrate 12 Terabytes of data which contained over 1.5 billion sensitive patient records that dated back to 1989. The BJSS delivery included a complete rewrite of the entire HES system.

BJSS Delivered

BJSS loaded backups into the UAT server and completed the migration in yearly phases. Results were checked and automatic row counts implemented. Once certain of the integrity of the migration, it was moved to the production server. Today data is stored in a single partitioned database that utilises a relational model.


The replacement system provides substantial manpower, processing and cost savings. Its new code base is much smaller and simpler and changes are easier to implement. The migrated data, which dates back to the late 1980s, is able to be quickly and efficiently mined, allowing the client to benefit from quick and insightful reporting.