Lean metrics, A3 thinking, and hoshin planning
Lean metrics, A3 thinking, and hoshin planning tests whether you can connect measures to purpose, tell a coherent PDCA story on one page, and deploy strategy through aligned experiments rather than slogan lists.
Core rules
- Use leading and lagging measures. On-time delivery is lagging; WIP, andon response time, and standard work audit completion are leading. Define every metric operationally: numerator, denominator, time period, and owner.
- OEE = availability × performance × quality. It is only useful when the definitions of planned time, ideal cycle, and good units are consistent.
- An A3 is a thinking process, not a form: background, current condition, target, root cause, countermeasures, plan, and follow-up. It should show evidence and a clear owner.
- Hoshin kanri aligns long-term objectives, annual goals, and daily work through catchball, X-matrix deployment, and regular reviews. Breakthrough objectives need a few vital priorities, not a long list.
- Review results with hansei: what was learned, what will be changed, and what remains unresolved. Adjust the plan rather than hiding variance.
Worked example
A line has 480 planned minutes, 48 minutes of downtime, 410 units produced, an ideal cycle of 1 minute, and 400 good units. Availability = (480 − 48) / 480 = 90.0%. Performance = 410 / 432 = 94.9%. Quality = 400 / 410 = 97.6%. OEE = 0.900 × 0.949 × 0.976 = 83.4%. The reasoning: each factor answers a different question-time lost, speed lost, and good-output loss-so an improvement plan should target the largest credible loss, not just announce raise OEE. Verify data definitions before comparing to another line.
Traps
Do not compare OEE across plants without common definitions. Do not use an A3 as a justification document with no test or follow-up. Do not turn hoshin into a list of every project. Do not chase a metric without checking whether it drives the intended behavior.
Key points
- Metrics need operational definitions and leading/lagging balance.
- OEE = availability × performance × quality; definitions must match.
- A3 is PDCA thinking with evidence, countermeasures, and follow-up.
- Hoshin aligns few vital priorities through catchball and review.