Fan-Out / Fan-In Orchestration

When to Use

• OST has 2+ solutions for the same opportunity that need parallel exploration
• Independent delivery work items that can be parallelized
• Multiple research streams needed simultaneously

Workflow

1. Prepare (Lead Agent)

• Read canvas/opportunities.yml
• Identify solutions needing parallel work
• For each: identify riskiest assumption and design test

2. Fan-Out (Spawn Workers)

For each solution:

• Spawn subagent or Agent Team member
• Provide: clear task, read-only canvas context, worktree isolation, time bound
• Each worker runs independently

3. Fan-In (Collect Results)

• Collect all worker results
• Update ICE scores in canvas
• Run /bias-check on combined findings
• Select winner(s) based on evidence
• Log decision in decision-log.md

Leaf Bakeoff Mode

When comparing competing OST leaves for the same opportunity:

• Each worker returns a structured scorecard (Four Risks + ICE + assumption test result + segment fit)
• Lead agent applies winner selection rules: clear winner (>20% ICE delta), close race (tiebreaker), segment split (both advance), both fail (archive and re-evaluate)
• Losers are archived to canvas/archived-solutions.yml with full evidence snapshot

See .claude/orchestration/leaf-bakeoff.md for the complete bakeoff protocol.

Rules

• Workers NEVER write to canvas (lead agent does)
• Workers NEVER progress diamonds
• Lead agent ALWAYS runs bias check on combined results
• Minimum 2 workers for meaningful comparison
• Maximum 3 leaves per bakeoff (respects L3 WIP ceiling)

See .claude/orchestration/agent-teams.md for full orchestration patterns.