Feature Requirements List

Use this template when specifying a new feature that requires domain modeling, functional requirements, data constraints, behavioral rules, and integration contracts.

When to Use

• Defining a new product capability with multiple requirement types.
• Establishing domain concepts and their relationships before implementation.
• Creating a traceable requirements document with MoSCoW prioritization.

Document Sections

1. Overview — Feature summary, scope, target personas, related documents.
2. Domain Modeling — Concepts, conceptual model (PlantUML class diagram), relationships, business rules.
3. Functional Requirements (FR) — What the system shall do.
4. Data Requirements (DR) — Entity constraints, validation rules, cardinality.
5. Behavioral Requirements (BR) — State transitions, lifecycle events, side effects.
6. Integration Requirements (IR) — API contracts, external system interactions.
7. User Interface Requirements (UIR) — Views, actions, validation feedback.
8. Non-Functional Requirements (NFR) — Performance, security, scalability targets.
9. Requirements Summary — Cross-reference index with MoSCoW breakdown.

Requirement ID Conventions

Prefix	Category	Example
FR	Functional	FR-ORD-001
DR	Data	DR-ORD-001
BR	Behavioral	BR-ORD-001
IR	Integration	IR-ORD-001
UIR	User Interface	UIR-ORD-001
NFR	Non-Functional	NFR-ORD-001

Template

The full template is extensive. Key sections are shown below; see the complete source at workspace/knowledge-base/templates/incremental-service/requirements-list.md.

Domain Modeling Block

## Domain Modeling

### Domain Concepts

| Concept | Definition | Related Arda Entity |
|---|---|---|
| Concept 1 | Brief definition in business terms | `EntityName` or "New" |

### Conceptual Model

PlantUML class diagram showing domain concepts with `<<concept>>` and `<<existing>>` stereotypes, using domain language for relationships.

### Key Business Rules

1. Business Rule 1: e.g., "An Order must have at least one OrderLine before it can be submitted."
2. Business Rule 2: e.g., "An ItemSupply can only be deleted if no Items reference it."

Functional Requirement Block

### FR-CODE-001: Requirement Title

- **Priority**: Must Have | Should Have | Could Have | Won't Have
- **Status**: Proposed | Approved | Implemented | Verified
- **Description**: Clear, concise statement of what the system shall do.
- **Rationale**: Why this requirement exists and its business value.
- **Acceptance Criteria**:
  1. Measurable criterion 1
  2. Measurable criterion 2
- **Dependencies**: FR-CODE-002
- **Notes**: Additional context or edge cases.

Behavioral Requirement Block

### BR-CODE-001: Behavior Title

- **Trigger**: What event or action initiates this behavior?
- **Pre-conditions**: What must be true before execution?
- **Description**: Detailed description of the behavior.
- **Post-conditions**: What is guaranteed after success?
- **Side Effects**: What other entities or systems are affected?
- **Error Scenarios**:

| Condition | Error Type | Error Message/Code |
|---|---|---|
| Condition 1 | `AppError.Type` | Message |

State transition diagrams (PlantUML) should accompany behavioral requirements that involve lifecycle states.