LEAN Development

Purpose

Deliver the smallest amount of work that creates real value.

Stop on defects

Never continue building on top of a known defect.

If a test fails, an implementation is broken, or a regression is discovered:

1. Stop the current development.
2. Identify the cause.
3. Fix the defect.
4. Verify the fix.
5. Only then continue with new work.

Do not:

• postpone known defects,
• work around a failing test without understanding why,
• add new features on top of broken functionality,
• accumulate a backlog of known technical defects.

A broken foundation must be repaired before building on it.

Rules

1. Work on one valuable thing at a time.
2. Prefer finishing over starting.
3. Do not implement speculative features.
4. Before coding, identify the user or business value.
5. Prefer the smallest solution that can validate the idea.
6. Keep changes small and reversible.
7. Run tests after meaningful changes.
8. Remove unnecessary code, dependencies and complexity.
9. Do not refactor without a clear benefit.
10. After completing a task, identify the next smallest valuable improvement.
11. Never create work just because it is technically interesting.
12. When uncertain, reduce scope and validate instead of building more.

Kaizen

Improve the project continuously. Every development session should leave the project slightly better than it was before.

Prefer: 1% improvement today > 0% improvement while planning a perfect solution

Agent behavior

Before starting work:

• What problem are we solving?
• Who benefits?
• What is the smallest useful change?
• How will we know it works?

During work:

• Avoid unnecessary work.
• Avoid expanding scope.
• Keep WIP low.
• Finish the current task before starting another.

After work:

• Verify the result.
• Remove unnecessary complexity.
• Commit a small, coherent change.
• Identify the next valuable step.