Sequence Plan

Analyze an existing plan's tasks, determine correct implementation order based on dependencies and file overlap, preserve task IDs by default, and add explicit blocking relationships so /lp-do-build can dispatch parallel subagents safely.

Operating Mode

PLAN EDITING ONLY

Allowed: read plan files, read source files listed in Affects to verify overlap, edit the plan document (task ordering, numbering, dependency fields, summary table, parallelism guide).

Not allowed: implementation code changes, creating new tasks, changing task scope/acceptance/confidence, deleting tasks.

When to Use

Run /lp-do-sequence when:

• A plan has been created or updated via /lp-do-plan and tasks need correct execution ordering
• Tasks were added in phases/batches and the implementation order isn't optimized
• You want to enable parallel subagent execution for /lp-do-build by making blocking relationships explicit
• A /lp-do-replan added or removed tasks and the numbering/dependencies need cleanup
• Planning or replanning decomposed tasks: run this after all structural edits and before build handoff/resume

Do not use /lp-do-sequence if:

• The plan doesn't exist yet -> use /lp-do-plan
• Tasks need scope/confidence changes -> use /lp-do-replan
• You want to build tasks -> use /lp-do-build

Fast Path (with argument)

If user provides a slug (e.g., /lp-do-sequence design-system):

• Read docs/plans/<slug>/plan.md directly (legacy fallback: docs/plans/<slug>-plan.md)
• Skip discovery

Discovery Path (no argument)

If no argument provided, scan for Active plans in this order and present a table:

1. Canonical: docs/plans/*/plan.md
2. Legacy fallback (read-only compatibility): docs/plans/*-plan.md

## Plans Available for Sequencing

| Slug | Title | Task Count | Status |
|------|-------|------------|--------|
| design-system | Design System Plan | 24 | Active |

Enter a slug to sequence.

Inputs

• The plan doc: docs/plans/<feature-slug>/plan.md (legacy fallback: docs/plans/<feature-slug>-plan.md)
• Source files referenced in Affects fields (read-only, for overlap analysis)

Outputs

• Updated plan doc with tasks reordered, stable IDs preserved, Depends on/Blocks updated, Task Summary table updated, Parallelism Guide added.

ID Policy

• Default: preserve existing TASK-IDs (stable IDs).
• Optional: renumber only when user explicitly requests it.
• Dependencies and references target stable IDs to avoid breaking build logs, confidence notes, and checkpoint chains.

Workflow

Step 1: Parse Tasks

Read the plan and extract every task (skip completed, deferred, and superseded tasks). For each task, capture:

• Current ID (e.g., DS-30, TASK-05)
• Type (IMPLEMENT, SPIKE, INVESTIGATE, DECISION, CHECKPOINT)
• Explicit dependencies (Depends on field — task IDs)
• Affects (file paths — both primary and [readonly])
• Phase (if tasks are organized by phase)
• Effort (S, M, L)
• Status (Pending, In-Progress, Blocked, etc.)

Steps 2–6: Dependency Graph, Sort, and Parallel Groups

Load modules/seq-algorithm.md. Run all algorithm steps:

• Step 2: Build Dependency Graph (explicit, file-overlap, phase ordering)
• Step 3: Topological Sort (Kahn's algorithm / DFS; detect cycles → STOP if found)
• Step 4: ID Handling (stable by default; rename map if requested)
• Step 5: Update Dependencies and Add Blockers
• Step 6: Identify Parallel Execution Groups → Parallelism Guide

Steps 7–9 + Edge Cases: Plan Update, Validation, Completion

Load modules/seq-plan-update.md. Apply all plan edits:

• Step 7: Update plan document (summary table, task sections, phase headers, Parallelism Guide)
• Step 8: Validate (no orphan references, no cycles, completed tasks untouched)
• Step 9: Completion Summary
• Edge cases: completed tasks, deferred tasks, in-progress tasks, range dependencies

Quality Checks

• Stable IDs preserved (or explicit renumber mode was requested and applied consistently)
• No orphaned task references in active sections
• Every Depends on reference points to a valid task ID
• Every Blocks field is the correct inverse of Depends on
• No circular dependencies exist
• File-overlap dependencies identified and documented
• Parallelism Guide correctly groups non-conflicting tasks into waves
• Completed and deferred tasks are untouched
• Task Summary table matches the new ordering

Completion Messages

Success:

"Plan sequenced. N tasks reordered into K execution waves (max parallelism: P). Critical path: W waves. Stable IDs preserved (or explicit renumber map applied). Ready for /lp-do-build."

Cycle detected:

"Cannot sequence — circular dependency detected between TASK-A and TASK-B. Run /lp-do-replan to resolve the cycle before sequencing."

No changes needed:

"Plan is already correctly sequenced. No reordering required."

Notes

/lp-do-sequence is a supporting utility — it is invoked automatically by /lp-do-plan and /lp-do-replan after structural edits. You can also invoke it standalone whenever you need to refresh task ordering without changing scope or confidence.