Layer 2: Structure
Scope: the whole [subject], divided into parts, with the seams between them and with the outside.
1. Parts
- Part A (part): [its one responsibility].
- Part B (part): [its one responsibility].
- Part C (part): [its one responsibility].
2. Standing (optional)
3. Seams between parts
4. Seams with the outside (optional)
- Part A to [actor or outsider]: [what crosses and why]. Part A initiates when [what starts it].
- [Outsider] to Part C: [what crosses and why]. [Outsider] initiates when [what starts it].
5. Shared things (optional)
6. Scenario paths (optional)
- V1. Given […], when […], then [Part A] [does what], and [Part B] [does what].
- V2. Given […], when […], then [Part B] [does what].
7. Costs (optional)
- C2.1. Given [the condition or volume], when [the subject is built, run or changed], then it costs [the amount, or Not supplied: the figure]. Paid by [who].
8. Risks (optional)
- R2.1. Given [a situation], when [it goes wrong], then [the harm]. Severity: [High, Medium, Low or Not rated]. Answered by [the id of a decision, assumption or rule, or Not supplied: the answer].
9. Open Concerns (optional)
- O2.1. Given [the unsettled situation], when [what would settle it happens], then [what follows, and what it feeds]. Raised by [who].
10. Assumptions
- A2.1. [What the division takes as true]. Basis: [why we think so]. If wrong: [what changes].
11. Decisions
- D2.1. [Why a part is a part of its own, or why two parts were kept apart]. Reason: [why].