After documenting your existing environment, it is time to decide which migration approach you want to follow. In the case of an iterative approach, which is usually recommended, you should start to plan which subject area and corresponding processes to migrate first.
To provide you with some guidance, establish a method to identify dependencies between your data sets and corresponding dashboards. A good starting point is an information matrix between your subject areas and analytical applications. In case you already have an information matrix in place as part of your DWH documentation, that is a good starting point. The following is a simplified example:
Documenting these dependencies helps you identify which data sets and ETL processes to migrate in your first and subsequent iterations. For your first subject area, we recommend selecting a subject area with medium complexity and high business outcome; for example, the migration will help speed up business critical reports.
After prioritizing the data sets and ETL processes, it is time to plan and document your migration efforts:
- Business outcomes and expectations
- Timeline for the migration including any hard deadline
- A detailed migration execution plan
- Cost estimation
