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 .claude/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
/mycelium:bias-checkon combined findings - Select winner(s) based on evidence
- Log decision in .claude/harness/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
.claude/canvas/archived-solutions.ymlwith full evidence snapshot
See ${CLAUDE_PLUGIN_ROOT}/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_PLUGIN_ROOT}/orchestration/agent-teams.md for full orchestration patterns.