Kaizen

Origin. Post-war Japanese manufacturing; systematized at Toyota by Taiichi Ohno and Shigeo Shingo (1950s-1970s); the word means "change for better."

Mechanism. Continuous incremental improvement by everyone, every day. Large improvements are decomposed into small changes; small changes accumulate. The mechanism is cultural as much as procedural: improvement is not a project but a stance. Workers closest to the process identify improvements because they see the waste that managers cannot.

Procedure. Observe the current process. Identify one small improvement — not the largest, but one achievable today. Implement it. Measure the result. Standardize if successful. Repeat. Never stop. The improvements are small enough that they require no approval, no budget, no project plan. The iteration rate, not the step size, produces the cumulative effect.

Applies to. Any process that will be repeated. Manufacturing, service delivery, software development, personal productivity.

Limitations. Local optimization that degrades the whole. Each station optimizes its own throughput; the line becomes unbalanced and inventory accumulates. Kaizen must be guided by system-level metrics, not just local metrics. Also: relentless improvement without stability produces change fatigue. The Toyota system alternates kaizen (improvement) with standardization (holding the gains).