Continuous Improvement Tools and Methods
This section covers continuous improvement tools and methods. The exam tests whether you can select and sequence methods, apply them to a defined problem, and lock in gains with standard work, not whether you can define tools in isolation.
Core methods
- PDCA and A3 thinking: plan from a problem statement, current state, target, and root cause; check with data.
- Standard work: takt, work sequence, and standard in-process inventory; the baseline for improvement.
- 5S, SMED, poka-yoke, TPM, kanban and pull, heijunka, andon, and jidoka.
- Root-cause analysis: 5 why, fishbone, Pareto, and gemba observation.
Small, frequent PDCA cycles grounded in gemba observation usually beat large annual projects.
Worked example
A machine stops repeatedly. Five why: Why stopped? Overload trip. Why? Bearing seized. Why? Insufficient lubrication. Why? Pump delivered low flow. Why? Worn pump shaft. Why? No inlet filter, so debris entered. Countermeasure: install the filter and add it to the preventive-maintenance standard. Stopping at operator forgot to lubricate would have produced a reminder poster, not a fix. Verification: track stops for six weeks; if they fall to near zero, update the standard and share it.
Traps that cost marks
- Selecting a tool before defining the problem; we need 5S is not a problem statement.
- 5 why ending at human error, which is almost never a root cause.
- 5S run as a cleanup campaign with no standards or audits.
- Kanban without leveling, discipline, or reliable replenishment.
- Kaizen events that end without standard work, an owner, and follow-up.