Learn · Data model
What is a BI data model?
A BI data model is how you arrange tables so business questions can be calculated consistently. It is usually a star-style shape: fact tables for events you measure, dimension tables for how you slice, and a calendar when time matters.
Not a copy of the ERP
Source systems are built to capture transactions. Reports are built to answer questions. Dumping every table onto a Power BI canvas creates relationships that fight DAX and dashboards that nobody trusts.
Fact tables hold measurable processes (orders, visits, invoices). Dimensions hold the nouns (customer, product, site, date). Star schema is simply the most common way to draw that so filters behave.
Why KPIs and DAX depend on it
A KPI such as occupancy by club this month needs a fact at stay or visit grain, a site dimension, and a date table. Without that, no generator can invent a correct measure. Modelling is how you make the dashboard calculable.
How BiDesignLab uses this
You provide table and column structure — not production rows. AI proposes a reporting model: facts, dimensions and relationships. Star schema is part of that job, which is why it does not get a separate thin page.
Questions
- Do I need a warehouse first?
- You need a clear structure. A warehouse helps operations; it is not a prerequisite for designing the reporting model. Loading and refresh stay in your BI tool.