# AI System Design Brief

Toolkit schema: `PAISEH-TK-1.0`
Source artifacts: Chapter 1 **AI Systems Engineering Definition and Principle Set**; Chapter 2 **AI System Stack Reference Model**; Chapter 12 **Reference Architecture Catalog**

Complete `../common-artifact-header.md` first. This brief establishes responsibility, boundary, system shape, and open design decisions. It references, rather than replaces, focused discipline records.

## 1. Problem and Responsibility

- Business and user problem:
- Current workflow and baseline:
- Proposed product responsibility:
- Minimum useful outcome:
- Why AI is appropriate:
- Credible simpler alternative:
- Explicit non-goals:

## 2. People and Authority

- Direct users:
- People affected by outputs or actions:
- Operational teams:
- Accountable product owner:
- Accountable decision owner:
- Decisions reserved for people:
- Appeal, correction, or override path:

## 3. System Boundary and Interfaces

- Inputs and source-of-record boundaries:
- Outputs and downstream consumers:
- External effects:
- Material dependencies:
- Trust, permission, and execution boundaries:
- Durable state and ownership:

## 4. Engineering Shape

| Layer | Responsibility | Authoritative artifact/version | Owner | Material interface or invariant |
| --- | --- | --- | --- | --- |
| Business problem | | | | |
| Engineering problem | | | | |
| Architecture | | | | |
| Evaluation | | | | |
| Harness | | | | |
| Context | | | | |
| Prompt | | | | |
| Foundation model | | | | |
| Infrastructure | | | | |

- Selected architecture pattern or composition:
- Credible alternatives and rejection reasons:

## 5. Consequence and Failure

- Credible failure scenarios:
- Maximum blast radius and exposure ceiling:
- Reversibility and correction:
- Safe degraded mode:
- Stop conditions:
- Recovery owner and verification:

## 6. Design Argument

| Claim or assumption | Evidence reference | Disconfirming evidence or limitation | Decision supported | Owner | Reopening event |
| --- | --- | --- | --- | --- | --- |
| | | | | | |

- Open decisions:
- Dependent artifact IDs:
- Current design disposition and conditions: