‘Source of truth’ in design is non-sense.
In software data schemes and such, it makes sense. There is a myth that you can liberally apply this mental modeling to design or design deliverables and the assets used by development to build software. Traceability, the more appropriate term and practice is what is useful, valuable and desirable in regards to the design to dev process. Why? Because there are multiple sources of truth in regards to a designed asset and it’s associated documentation, annotations, copy decks and or design system references.
One other thing, pattern references and heuristics and semantical references are more useful sources of reference rather than truth. This applies for QA, BA and any other delivery folks. Because the single sources of truth applies to data schemes and how architectures reference pieces of data and their relationships etc… I’m not an engineer. I went to art school and there were no single source of truth classes… Ugh, gross.
Why do people say this when there work has multiple points of reference?
To make matters worse there are many points of reference and truth about aspects of a design asset creation and annotation, QA, testing and acceptance criteria and more. I have a hypothesis; there is a desire to lazily determine a single source of truth for design things cause it makes peoples job easier and personal accountability and efficiency higher. Intellectual laziness to assume rightly or wrongly that there should be a single source of truthiness. Sadly there are multiple truths in everyones world, time keeping systems, statements of work, MSAs, Change Requests, SMS, IM, email… online bank statements, paper statements, those little slips that come out of the ATM, your odometer, your speedometer, the radar gun and so on.
Where does this Source of truth nonsense come from?
I linked to the reference to SSOT as it is referred to below. Here’s the thing, I you have a wildly complex project and needs all this single source mumbo jumbo, great. Stop applying this to design things. It’s frustrating. Now get back to work and wash your hands. You’re amazing.