We Thought We Solved That: The Art and Judgment Calls in the PDSA Cycle

Lean Blog by Mark Graban · Jul 14, 2026

An executive says, after hearing about a major quality defect: “You said we solved that. Why'd the problem come back???” That might sound like an attempt at accountability. But it's not necessarily Lean thinking. The “Study” step of the Plan-Do-Study-Adjust cycle is supposed to help us learn from what happened. Did the countermeasure work as expected? Did the process change? Did we misunderstand the cause? Did the old condition return because the system made it […] The post We Thought We Solved That: The Art and Judgment Calls in the PDSA Cycle by Mark Graban…