During data migration, information is transferred. This transfer could take place in a few ways: between data storage systems, data formats, or computer systems.
Challenge #1: Parallel run decision:
The migration strategy is defined along the planning phase, and parallel run is often one of the topics discussed with key business users. Altran believes that a parallel run migration strategy should be carefully taken, mainly because of the extra effort to maintain two systems in parallel, which can be challenging from both business and technical perspectives.
Challenge #2: Data cleansing:
Source data profiling obtains a quality measure of the current data, but migration projects usually require data cleansing to achieve the desired data quality level (data quality KPI) in destination system.
Data quality KPI objective is determined considering the following parameters:
- Data volume affected.
- Time available.
- Effort required.
- Benefits obtained.
Challenge #3: Different source systems, different coding and a unique data:
Quite often the same data is replicated in different systems, with one of the systems working as master and the rest as replica. However, sometimes, special cases may arise where the same data resides in multiple systems with different coding and there is no link between them. (e.g, a client company has contracted something as SMEs and it becomes a large company and it contracts different products / services). Special cases treatment requires analysis and agreement with key business users to make decisions about how to migrate them. Available options are:
- Group data in a single master data.
- Clear data and do not migrate it.
- Keep both master data and create hierarchy group for reporting purposes.
Challenge #4: Select ETL Tool:
During the analysis phase, it is also necessary to analyze the destination systems (bespoke and Commercial of the Shelf, COTS). This analysis allows identify reference model and any technical requirements to load data. In general, bespoke systems load data directly in DB, but COTS systems usually have their own data import/ export tools. The function of COTS import/ export tools can be grouped in two different types:
Type 1: to maintain specific traceability process within the COTS database (such as ERP).
Type 2: Load tools to perform frequently loading and/ or extraction (such as CRM).
Challenge #5: Validation and Test Migration:
Before performing migration in production, it is required to validate the migration results with key business users and to establish the correct timing for the migration tasks.
Concerning the migration results validation with key business users, Altran recommends to test destination systems (in both integration and User Acceptance Test environments at least) with migrated data. Integration and UAT test cases will identify issues with migrated data within a real business context.