How is data migration handled during application re-design?
Pre-Migration Assessment and Planning
- Data sources, structures, and volumes are identified and documented.
- Compatibility between legacy and redesigned application data models is evaluated.
- Data integrity, sensitivity, and compliance requirements are assessed.
- Migration strategy options such as phased, parallel, or big-bang are considered.
- A detailed migration plan is created, including scope, timeline, and rollback steps.
Data Mapping and Transformation
- Field-level mapping defines how old data aligns with the new schema.
- Transformation rules convert formats, units, and structures as needed.
- Redundant, outdated, and low-quality data is cleaned or excluded.
- Scripts and tools are prepared to automate mapping and validation processes.
- Reference data and master data are reviewed for consistency and completeness.
Testing and Validation Procedures
- Pilot migrations are conducted on subsets of data to test accuracy.
- Validation checks confirm data completeness, consistency, and referential integrity.
- Discrepancies between source and target data are logged and resolved.
- Business rules are verified to ensure correct functional mapping.
- Migration test results inform refinement of transformation scripts and schedules.
Execution and Monitoring
- Migration is executed during scheduled downtime or in parallel with legacy systems.
- Logging and monitoring tools track progress, performance, and exceptions.
- Error-handling routines are triggered for invalid or failed records.
- Performance is measured to ensure acceptable speed and resource usage.
- Real-time updates may be applied during extended migrations for synchronization.
Post-Migration Review and Optimization
- Final data validation ensures successful migration to the target environment.
- Reports document migrated records, errors resolved, and exceptions handled.
- Stakeholders review results and confirm business functionality of migrated data.
- Cleanup activities remove deprecated tables, logs, or temporary fields.
- Lessons learned are recorded to improve future migrations or audits.