Who it is for
Teams where developers still work broadly traditionally and AI assists inside that workflow: scaffolding, tests, review, research. This is where most organisations are today, and for those teams the full breakdown is still the right answer.
Teams where the model does the building and the developer directs and verifies it. Decomposing into stories here is counterproductive: it strips out the surrounding context the model needed, and pre-empts judgement the model is now capable of exercising itself.
A ticket is
A story. The smallest piece of user-visible value the team can ship, small enough to build in a sprint and specific enough to test.
An outcome ticket, written at epic level. It carries the outcome, its share of the currency target, the key user journeys, and the test requirements. It is written to be handed over whole, so it has to contain enough for someone to work from it without a follow-up conversation.
Work breaks down into
All four levels. Outcome, epic, story, and chapters where a developer needs to break a story down mid-build.
Three levels, not four. Outcome and epic. Stories and chapters do not exist, because the outcome ticket is the unit of work and splitting it below that loses more than it gains.
Before work starts
An epic cannot leave Ready for Dev without product approval, engineering approval and at least one product-approved story attached. A story cannot leave the backlog until its parent epic is product-approved.
The outcome is stated with its currency share, the key user journeys are listed, the test requirements are defined, and both product and engineering have approved. There is no child-story requirement, because the ticket already carries what a story used to prove.
Done means
The story's acceptance criteria are met and a human has reviewed the change.
Both, not either: the test requirements in the ticket pass, and the key user journeys named in the ticket are demonstrated working. A model reporting that it has finished is not evidence that it has.
It reaches the builder by
The story goes to a developer, who builds it and uses AI wherever it helps.
A product brief becomes outcome tickets, the tickets are prioritised, and each one goes either straight to a model or to a developer who runs it into a model and iterates until the outcome is met.