Prd 04 Flow Modeler

PRD Flow Modeler

Purpose

Translate rule logic into flows that show how users, systems, and states move through the feature.

Inputs

• Rule model.
• Scope boundary.
• Known entry points and target pages, if available.

Process

1. Identify entry points.
2. Write the happy path.
3. Write system judgment flow behind the happy path.
4. Write exception paths.
5. Write state transitions.
6. Identify where user-facing feedback is required.
7. Identify where system logging or operations visibility may be needed, but do not define full analytics here.

Flow rules

• Separate user behavior from system behavior.
• Include failure outcomes, not just success outcomes.
• Include empty, expired, permission-denied, duplicate, and network-failure states when relevant.
• Do not introduce new scope unless the rule model requires it.
• If the flow exposes missing rules, mark them as Rule gap and send them back to prd-03-rule-modeler.

Output format

# 03 Flow Model: {Feature Name}

## 1. Entry points
| Entry | User condition | Display condition | Destination |
|---|---|---|---|

## 2. User happy path
```mermaid
flowchart TD
  A[User sees entry] --> B[User opens feature]
  B --> C[User performs core action]
  C --> D[User receives result]

3. System judgment flow

flowchart TD
  A[Receive user action] --> B{Check feature status}
  B -->|Available| C{Check user eligibility}
  B -->|Unavailable| X[Return unavailable state]
  C -->|Eligible| D[Execute action]
  C -->|Not eligible| Y[Return reason]
  D --> Z[Update state and return success]

4. State transition table

| Object | From state | Trigger | To state | Notes | |---|---|---|---|---|

5. Exception flows

| Exception | Trigger | System behavior | User-facing response | Rule gap? | |---|---|---|---|---|

6. Handoff to next stage

Recommended next skill: prd-05-page-interaction

## Definition of done

The flow model is complete when engineering and QA can see the feature path without relying on narrative interpretation.

## Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

- **Author:** [baobao2333](https://github.com/baobao2333)
- **Source:** [baobao2333/prd-agent-kit](https://github.com/baobao2333/prd-agent-kit)
- **License:** MIT

Install and usage instructions live in the source repository linked above.