Dependency & Ordering Analysis

Identify prerequisite relationships between requirements so work can be sequenced. The deliverable is a directed acyclic graph (DAG) of FRs/StRs/NFRs in logical order, not a schedule.

When to use

• Before spec-to-plan — spec-to-plan consumes the DAG.
• After all FRs have been written and reviewed.
• Whenever new FRs are added that may unblock or block existing work.

Process

1. Identify prerequisite edges. For each FR/StR/NFR, list every other requirement that MUST be satisfied before this one can be implemented. Express each as A → B (A is prerequisite to B).

2. Classify each requirement.

   • Enablement — frameworks, abstractions, scaffolding, schema/migration, shared libs. Has no business-visible behavior on its own.
   • Feature — business or user-visible behavior.

   Rule: Enablement requirements MUST be tasked before any feature that depends on them.

3. Verify acyclicity. If any cycle is found, the spec is malformed — break the cycle by introducing a separation FR or merging the cyclic requirements.
4. Produce the deliverable. Use the template below.

Deliverable template

Record output in spec/analysis/dependency.md (or as a section in spec/spec.md § 7 if your project keeps analysis inline).

# Dependency Analysis

## Classification

| Requirement | Class | Rationale |
|-------------|-------|-----------|
| FR-001 | Enablement | Defines the auth middleware all feature FRs use |
| FR-002 | Enablement | Database schema for user records |
| FR-003 | Feature | Login flow — depends on FR-001, FR-002 |
| FR-004 | Feature | Password reset — depends on FR-001, FR-002 |

## Dependency Graph

​```mermaid
graph TD
  FR-001[FR-001: Auth middleware]
  FR-002[FR-002: User schema]
  FR-003[FR-003: Login flow]
  FR-004[FR-004: Password reset]
  FR-001 --> FR-003
  FR-002 --> FR-003
  FR-001 --> FR-004
  FR-002 --> FR-004
​```

## Topological Order (suggested implementation sequence)

1. FR-001, FR-002 (enablement, parallelizable)
2. FR-003, FR-004 (features, parallelizable after enablement)

## Cycles

None detected.

Acceptance Criteria

• Every FR/StR/NFR appears in the classification table exactly once.
• Every edge in the graph corresponds to an explicit prerequisite — no "soft" dependencies.
• No cycles.
• Topological order respects: all enablement before any feature that depends on it.