Planning and preparation provide the foundation for a successful eDiscovery data migration, but how that plan is executed can be just as impactful as the strategy behind it. Whether data is moved all at once or in stages, the process itself plays a critical role in maintaining operational continuity, minimizing risk, and preserving defensibility.
Evaluating Process Models: All at Once vs. Incremental Migration
The first major decision you’ll likely face is whether to migrate all data in a single event or use a phased approach. Each method has distinct advantages and trade-offs, and the right choice depends on the size of the dataset, the complexity of the environment, and your organization’s tolerance for risk.
All-at-Once Migration
A full-scale migration involves transferring the entire dataset in a single coordinated effort. This method provides a clear and decisive cutover to the new system, which simplifies tracking and eliminates the need to maintain two platforms in tandem. By minimizing overlap, it reduces the chance of versioning issues and user confusion.
However, the stakes are high. If errors occur during the migration, those errors can propagate across all matters. Downtime is often required during the transition window, which can disrupt user workflows. Quality assurance must be especially rigorous, as there is less room to course correct once the transfer is complete.
Incremental Migration
A phased approach, on the other hand, offers more control. Data is migrated in smaller, manageable batches, allowing for iterative validation and issue resolution. You can test workflows and performance before committing to a full transfer, which reduces risk and helps users acclimate gradually to the new system.
That flexibility, however, comes at a cost. Running two systems in parallel increases administrative overhead and introduces the risk of inconsistencies. You must carefully manage cross-platform dependencies, ensure that data changes in one system are reflected in the other, and maintain strict version control throughout the process.
Regardless of the chosen approach, you should define clear milestones, timelines, and decision checkpoints. These structures help avoid scope drift and ensure that each phase of the migration is aligned with business and legal objectives.
Sustaining Defensibility Through Process Discipline
Once the structure of the migration is established, the next priority is to ensure that the process itself supports legal defensibility. A sound data migration is not just one that moves data accurately. It must also be able to withstand scrutiny if challenged during litigation, an audit, or a regulatory review.
Maintaining defensibility requires active documentation and governance throughout the data migration lifecycle. A current and detailed statement of work, migration scope, and decision log should be maintained and updated in real time. These records demonstrate intent and control, and they provide transparency into how each decision was made and executed.
Grouping matters into defined tranches, such as business unit, case status, or data volume, adds structure to the migration and allows for repeatable, verifiable processes. This level of discipline not only drives operational consistency but also reinforces the defensibility of the migration strategy itself.
Maintaining Data Integrity During Migration
It’s important to note that defensibility depends heavily on data integrity. As files move from one system to another, the risk of corruption, exclusion, or misclassification increases. Preventing these outcomes requires close attention to how files are stored, handled, and validated throughout the process.
File system permissions must be consistent, and access controls should be reviewed to ensure that data isn’t inadvertently excluded due to restrictive settings. Hidden or nonstandard file locations, such as shared drives, temporary folders, or nested archive structures, must be identified early to avoid gaps in the data set.
In addition, non-document assets such as audit logs, production metadata, and active learning models must be included in the migration scope. These elements are critical to maintaining workflow continuity and historical context, and their absence can introduce significant operational and legal risk.
A detailed reconciliation process should confirm that all files have been transferred accurately after the data migration is complete. Any discrepancies should be flagged, investigated, and resolved before the migrated data is put into active use.
Conclusion
Even after the data has been moved, the data migration is not truly complete until your team can confidently operate within the new environment. That continuity requires more than just access. It demands context.
Audit histories, event logs, and legacy workflow configurations provide critical insight into how data was previously handled. Retaining this information, whether by importing it into the new platform or archiving it for reference, ensures that you can trace decisions, validate prior actions, and address questions about chain of custody or review methodology.
Additionally, documentation is just as important as data. Any changes made to deduplication logic, search syntax, tagging structures, or user roles during the migration should be clearly recorded and shared with relevant stakeholders. These adjustments shape how your team will interact with the system and influence everything from case strategy to production protocol.
By investing in a thoughtful transition, not just in moving the data, but in preserving its legal and operational context, you ensure that the migration supports not only present matters but future readiness as well.
Joey Adams
Author
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Joey Adams leads TCDI’s Systems Operations team, which is responsible for the day-to-day technical management of the company’s client-facing software. Since joining TCDI in 2001, Joey has held a range of roles from software development and implementation engineering to project management, on-site client support, and database administration.
Today, his team handles everything from software installations and second-level support to the technical aspects of data migrations. With more than two decades of industry experience, Joey brings a deep understanding of legal technology infrastructure and a hands-on approach to ensuring reliable, high-performing systems for TCDI’s clients. Learn more about Joey >
