Data Management, Analytics and Decision Support
From raw data to decisions
Data management covers the definition, storage, quality, protection and use of data as an asset. Analytics converts that data into insight, and decision support systems present insight at the point of decision. Candidates must be fluent in the data lifecycle and in the levels of analytics.
Concepts to master
- Data quality dimensions: accuracy, completeness, consistency, timeliness, validity and uniqueness. A question often describes a symptom and asks which dimension fails.
- Master and reference data: master data describes core entities (customer, product, supplier); reference data is the permitted value sets; transactional data records events.
- Metadata and the data catalogue: technical, business and operational metadata; lineage answers where a number came from.
- Data warehouse, data lake and lakehouse: schema-on-write versus schema-on-read, and the risk of an ungoverned data swamp.
- Analytics levels: descriptive (what happened), diagnostic (why), predictive (what is likely), prescriptive (what to do).
- Decision support: dashboards, key performance indicators, drill-down, exception reporting, and the risk of alert fatigue.
- Governance of analytics: data ownership and stewardship, quality rules, privacy constraints and model monitoring.
Traps in questions
- Confusing a data lake with a data warehouse; the lake stores raw data cheaply but needs governance to be useful.
- Mixing predictive and prescriptive. A forecast is predictive; a recommendation is prescriptive.
- Assuming more data always improves decisions; poor quality or biased data degrades them.
- Forgetting that a dashboard showing the wrong definition of a KPI is a governance failure, not a display problem.
Worked example
A sales report shows 1,200 orders while finance shows 1,150. Both extract from the same source. Check, in order: the definition of an order (cancelled and test orders included?), the extraction timestamp, and the join logic. The gap is most likely a consistency and definition issue, solved by a certified KPI definition and shared metadata rather than by rebuilding the dashboard.