Fable
The account page in the wall crack
The key here is to apply the concept's constraints to specific objects, rather than merely describing an outcome.
As scale and exceptions increased, the methods previously held together by ad hoc coordination began to expose blind spots.
Short-term patches restore surface order, but do not address what the concept truly constrains.
The old craftsman turned to recording conditions, actions, results and the chain of responsibility, so that subsequent adjustments had evidence to rely on.
The shopkeeper assigned each team its own cabinet, ledger pages, and horse troughs; even the shared kitchen took items by tag, and leftovers could not be mixed. This step was troublesome and at first slowed the work; but after several rounds, rework decreased, and the craftsmen no longer changed the rules on a whim. Everyone finally saw that tenant isolation must cover every piece of data and every execution path, and that cross-tenant testing must prove the boundary actually holds.
The inn still shared facilities, but each caravan's boundary could be verified.
The inn was still one building, but each other's things no longer leaked into the other's luggage. From then on, when multiple people shared one place, good isolation kept saving space from turning into mutual contamination.