Migration Issues
When migrating from an old system to a new system there are a number of risk factors involved in the data transfer process.
- Data Loss
- Data Corruption
- Data Duplication
- Security & Privacy Issues
- Timing Issues
These issues need to be identified and managed in order to successfully migrate to the new system
Data Loss
Data loss when transferring from an old system to a new system is a key concern.
Data loss can occur when:
- Data stored on the old system is forgotten about and discarded when moved to the new system
- Data doesn’t transfer as intended to the new system
- When the new system doesn’t a have storage model that matches the existing system and there has to be deliberately discarded
Not all data needs to be migrated from legacy system to a new system and therefore some data loss may be deliberate.
A thorough analysis of the data models for the old and new systems needs to be undertaken in order to identify data loss risks.
Data Corruption
Data corruption happens when data is altered during the transfer process. This can be caused by:
- Incompatible storage models, where the new model has a smaller capacity than the old system
- Incompatible data encoding, such as trying to migrate Unicode to ASCII
- Timezone inconsistency when moving between systems (local time vs GMT vs UTC)
Thorough testing and inspection of data needs to be undertaken, with special care taken with encodings and boundary cases.
Data Duplication
Data duplication is an issue when moving to new systems and although the duplication itself might not be an issue, it often results in:
- Increased storage and data processing requirements, especially when SQL queries are run on large tables
- Orphaned records that contain data that has not been correctly updated.
Security & Privacy Issues
Security and privacy of data are important concerns when migrating to a new system. Failure to ensure security and privacy can have serious consequences both financially and legally for the organisation. Issues include:
- Ensuring data is encrypted and secure during the transfer process.
- Ensuring that data to securely stored in the target system
- Ensuring that data is wiped from the legacy system
- Ensuring that those involved in the transfer process are correctly vetted and only have access to the data they need to do the job.
- Ensuring that user access privileges in the target system are set correctly to in order to maintain data privacy where appropriate
Timing Issues
Migrating data from an old system to a new system can be a time consuming and labour intensive process so the process needs to be managed in order to ensure that:
- Data is moved in an efficient and timely manner.
- Downtimes for systems are minimized and migration is done outside of business operational hours.
- Stakeholders are made aware in advance of any disruption and the timeframes anticipated so that they can take steps to mitigate issues that may arise.