DataViz Migration - migrating from Cognos to Power BI
IBM Cognos Analytics platforms typically hold several years’ worth of business modeling, whose value lies more in the Frameworks and business rules than in the reports themselves.
Analysis of the Cognos estate
{openAudit} analyzes Framework Manager, reports, queries, dimensions, hierarchies, calculations, filters, and variables, and reconstructs dependencies between objects, relationships with data sources, and the business objects and indicators exposed in reports.
Scope rationalization
Cross-referencing usage logs with the metadata identifies unused reports, duplicates, and obsolete Frameworks.
Result: the scope that’s actually used is isolated before migration.
Conversion to Power BI
Cognos Frameworks are converted to the Power BI semantic model: dimensions, hierarchies, measures, calculations, variables, and relationships between objects are reconstructed there, Cognos expressions are converted to SQL or DAX depending on their nature, and dependencies between Frameworks, reports, and sources are preserved.
The conversion relies on {oa-lake}: calculations and business rules are encapsulated as SQL pipelines, and business objects feed its interoperable semantic layer, which Power BI connects to (see below).
Validation
During acceptance testing, Cognos and Power BI run in parallel and their indicators are compared before cutover.
Usage-driven migration
Reports are migrated in batches, prioritized by how often they’re used and their business criticality.
Result: a reduced volume to migrate, with effort focused on active usage.
{oa-lake}: the foundation of every dataviz migration
Moving from one reporting tool to another meets the immediate need, but it shifts the business logic into a new proprietary model: the next time the tool changes, everything has to be rebuilt again.
Power BI connects to {oa-lake} and consumes a ready-made model: business objects, KPIs, and security are no longer locked into a new proprietary model.
Key point: migrating to {oa-lake} means migrating one last time. Business logic becomes a company asset, independent from vendors.
Why {oa-lake} underpins every dataviz migration → · Discover {oa-lake} → · SQL interoperability and semantic layer →
