What it is not
A single source of truth is smaller than it sounds, and easier to lose than it looks.
The phrase gets read as "one system to rule them all", which makes it sound like a migration project. It is not. It is a per-field decision about authority, and most teams lose it not by choosing the wrong system but by letting a second copy quietly become editable.
Three misreadings
What it does not mean
It does not mean one system for everything. The CRM can be authoritative for deal stage while the finance system owns invoice status. Source of truth is assigned per fact, not per tool.
It does not mean the other copies vanish. Dashboards and reports still show the number, they just read it from the authoritative source and never overwrite it. Displaying a value and owning it are different jobs.
It does not mean read-only data. The authoritative source is edited constantly. The rule is only that it is the one place edits happen, so everywhere else reflects those edits rather than competing with them.
