Plan kit · work-shapes
When work outgrows one plan, four shapes cover every split. The choice is ownership and coupling, never headcount or line count. The umbrella sits on top of them, an overlay, not a fifth shape.
the four shapes
A coherent deliverable that fits one implementation session.
One deliverable across several sessions or PRs. One lifecycle and estimate; each session hands off to the next.
Separable ownership or release timing, the default for separate frontend and backend devs. A scope boundary and depends_on keep them aligned.
Tightly coupled: a shared migration or an atomic release that cannot be reviewed or shipped independently.
A coordination plan above several Shape C or D atoms: a shared sequence and a program close gate. Each child atom keeps its own plan; the umbrella never duplicates one. It is delivery coordination, not an Epic (a requirement grouping).
how to choose
The split follows ownership and coupling, not headcount: two devs on one inseparable change is still D; one dev on two independently useful outputs can still be C. Shapes B and D are the pair people conflate: B is one atom over several sessions, D is several atoms in one plan.