Every department has a dashboard and none of them agree. The cause is four systems each answering the question differently, with nothing above them deciding which one is right.
Most BI projects start with dashboards and discover the disagreement later. Starting with the definition is slower for a fortnight and faster for every year after that.
Scheduled loads from each source system with failure alerting, so a silent pipeline break doesn't poison a quarter of reporting.
Facts and dimensions modelled for the questions the business asks, rather than a copy of each source schema stacked in one place.
Logic in version control, reviewed and testable, so a change to how margin is calculated is a visible commit rather than a mystery.
One definition of revenue, customer, and churn that every report reads from. This is the part that ends the disagreement.
Built for the decisions people make, not for everything that could be plotted. Most dashboards fail from excess rather than absence.
Every report showing when its data last loaded, because a number without a timestamp gets distrusted and then ignored.
The symptom is a meeting spent reconciling numbers instead of acting on them. That hour repeats weekly until something above the source systems decides what is true.
Getting data out of the source systems is data integration; the modelling underneath is database design.
Tell us which report nobody trusts and which systems feed it. We'll map where the definitions diverge and what a warehouse would need to hold to settle it.