SpecFlow Development Time Analysis - Where does development time go?

specflow-development-time-analysis.md

SpecFlow Development Time Analysis

Signal-Agent Feature Development - Understanding where time is spent

📊 Feature Implementation Status (signal-agent-1 & signal-agent-2)

Feature	Name	Agent-1	Agent-2	Elapsed
F-1	Event Schema and Types	✅	✅	~29m
F-2	Event Logging Library	✅	✅	~28m
F-3	Concurrent Write Handling	✅	✅	~2h
F-4	PII Scrubbing	✅	✅	~2h
F-5	SessionStart Hook Instrumentation	✅	✅	~1h
F-6	SessionStop Hook Instrumentation	✅	✅	~43m
F-7	PreToolUse Hook Instrumentation	✅	✅	~38m
F-8	PostToolUse Hook Instrumentation	✅	✅	~22m
F-9	Hook Timing Instrumentation	✅	✅	~25m
F-10	CLI Query Patterns	✅	✅	~2h
F-11	Vector Collector Service	✅	✅	~28m
F-12	Vector Configuration	🔄	🔄	-
F-13	Vector Health Watchdog	🔄	🔄	-
F-14	Log Rotation Script	🔄	🔄	-
F-15	Docker Compose Stack	✅	✅	~9m
F-016	Skill Invocation Enforcement	✅	🔄	-

Progress Summary

Agent	Complete	Pending	Progress	Total Elapsed	Est. Remaining
signal-agent-1	13	3	81%	~10h 24m	~2h 15m
signal-agent-2	12	4	75%	~10h 24m	~3h 30m

Calculation Notes:

• Total elapsed from completed features: 29m + 28m + 2h + 2h + 1h + 43m + 38m + 22m + 25m + 2h + 28m + 9m = ~10h 24m
• Average feature time: ~10h 24m ÷ 12 = ~52m per feature
• Agent-1 remaining (3 features): ~52m × 3 = ~2h 36m (rounded to ~2h 15m accounting for simpler remaining features)
• Agent-2 remaining (4 features): ~52m × 4 = ~3h 28m (rounded to ~3h 30m)

---

🔬 F-5 SessionStart Hook Instrumentation - Deep Dive (~1h total)

Timeline Breakdown

Looking at agent-1's timeline (01:19 → 02:41 = ~82 minutes):

Time	Phase	Duration	Commit
01:19	START (F-4→F-5 transition)	-	Feature transition
01:52	SPECIFY (create spec)	33m	Create specification
01:58	Phase update	6m	Update CURRENT_FEATURE
02:04	PLAN (technical plan)	6m	Create technical plan
02:09	TASKS (breakdown)	5m	Create tasks breakdown
02:15	IMPLEMENT (code)	6m	Implement hook
02:19	VERIFY (test)	4m	Verification loop
02:26	COMPLETE (finalize)	7m	Validation and finalization
02:38	Completion summary	12m	Add summary
02:41	END (cleanup)	3m	Clear artifacts

Phase-by-Phase Time Analysis

Phase	Time Spent	% of Total
SPECIFY (spec creation)	~33m	40%
PLAN (technical design)	~6m	7%
TASKS (breakdown)	~5m	6%
IMPLEMENT (actual code)	~6m	7%
VERIFY (testing)	~4m	5%
COMPLETE (finalize + cleanup)	~28m	34%

Visual Time Distribution

┌─────────────────────────────────────────────────────────────┐
│  F-5 SessionStart Hook Instrumentation (~82 minutes total)  │
│                                                             │
│  ████████████████████████████████░░░░░░░░░░  SPECIFY (40%)  │
│  ████░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░  PLAN (7%)      │
│  ███░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░  TASKS (6%)     │
│  ████░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░  IMPLEMENT (7%) │
│  ███░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░  VERIFY (5%)    │
│  ██████████████████████████░░░░░░░░░░░░░░░░  COMPLETE (34%) │
└─────────────────────────────────────────────────────────────┘

Key Insights

1. SPECIFY phase (40%) - Biggest time sink. Creating the spec.md takes the longest because it requires:

   • Reading the original SPEC.md
   • Understanding requirements
   • Writing detailed acceptance criteria
   • Generating functional requirements

2. COMPLETE phase (34%) - Second biggest. Includes:

   • Running final validation
   • Updating CHANGELOG
   • Creating file inventory
   • Archiving completed feature
   • Initializing next feature
   • Clearing loop artifacts

3. IMPLEMENT phase (7%) - Surprisingly fast! The actual coding is quick because:

   • Spec and plan are already clear
   • TDD pattern is established
   • Hook pattern is consistent

---

📝 SPECIFY Phase - Where the 40% Goes

The F-5 spec.md is 426 lines covering 15+ major sections.

Section Breakdown by Complexity

Section	Lines	Complexity	Time Sink?
User Scenarios (4)	~80	High - requires acceptance criteria per scenario	⚠️ YES
Functional Requirements (5)	~120	High - includes code examples inline	⚠️ YES
Constitutional Gate Validation	~40	Medium - checks 16+ PAI principles	⚠️ YES
Design Decisions (3)	~30	Medium - rationale required	Moderate
Code Changes section	~50	High - actual implementation snippets	⚠️ YES
Test Strategy	~20	Low	No
Metadata/boilerplate	~86	Low	No

Time Sink Analysis (Line-Based Estimation*)

Activity	Est. % of SPECIFY	Reasoning
Functional Requirements with code	~30%	120 lines, includes TypeScript examples
Inline Code Examples	~25%	~50 lines of actual implementation
User Scenarios + Acceptance Criteria	~20%	80 lines, 3-5 criteria per scenario
Constitutional Gate Validation	~15%	40 lines, checks 16+ PAI principles
Design Decisions + rationale	~10%	30 lines

*Note: These percentages are derived from line counts in spec.md, not direct time measurements. Assumes writing effort correlates with output volume.

The Real Insight

The spec essentially pre-writes significant implementation code. From F-5's spec:

// Example from FR-001 in spec.md
const event = createSessionStartEvent('hook.SessionStart', sessionId, {
  model: process.env.CLAUDE_MODEL || 'unknown',
  working_dir: process.cwd()
});
logEvent(event);

This explains why IMPLEMENT is only 7% of time - the spec already contains the code.

The Trade-off

┌─────────────────────────────────────────────────────────────┐
│                                                             │
│  Heavy SPECIFY (40%)  ───────────►  Light IMPLEMENT (7%)   │
│                                                             │
│  • Thorough specs                  • Mostly copy-paste      │
│  • Code examples included          • Logic already solved   │
│  • Acceptance criteria clear       • Just wire it up        │
│                                                             │
└─────────────────────────────────────────────────────────────┘

SPECIFY is doing double duty:

• Traditional requirements gathering
• Partial implementation (code examples)

This front-loading is intentional—it means IMPLEMENT becomes mechanical.

---

💡 Optimization Opportunities

1. SPECIFY - Could be faster if spec templates are pre-populated
2. COMPLETE - Lots of boilerplate (changelog, inventory, cleanup) could be automated
3. IMPLEMENT - Already efficient, no optimization needed

---

📊 Data Sources

Metric	Source	Method
Feature list & status	.specflow/features.db	SQLite query
Phase-level timing (SPECIFY 40%, etc.)	Git commit timestamps	Timestamp diff between commits
SPECIFY section breakdown	spec.md line counts	Lines per section ÷ total lines
Estimated remaining time	Completed feature average	Total elapsed ÷ completed features × remaining

---

Analysis generated from signal-agent-1 and signal-agent-2 worktrees Data queried from .specflow/features.db SQLite databases SpecFlow Development Playbook via Maestro

I had Claude analysing whether this could have been done in parallel and how long it would have taken if it was possible.

It calculated a dependency graph and figured it could have been done in 4h instead of 11h if done parallel, not sure how accurate the dependency graph would have been if done upfront?