Plan-do-check-act (PDCA) is a management concept that emphasizes continuous improvement and has significantly influenced both manufacturing and modern product management. Originating from the scientific method, the PDCA cycle was formalized by W. Edwards Deming, who introduced it to Japan in 1950, prompting its integration into the Toyota Production System, which revolutionized manufacturing with its focus on high-quality production and lean methodologies. PDCA revolves around a cycle of planning, executing, checking outcomes, and acting on insights to optimize processes, and it has become integral to agile product management by enabling organizations to adapt to fast-paced changes and uncertainties in the market. The cycle encourages a learning mindset, openness to unexpected results, and an outcome-focused approach, allowing for iterative development and informed decision-making. In agile frameworks such as Scrum, PDCA is embedded in multiple learning cycles that enhance team collaboration, product value, and sprint goals, proving essential for fostering a learning culture within organizations. With its emphasis on adaptability and continuous learning, PDCA remains a foundational element for both lean manufacturing and agile practices, ensuring efficient progress towards defined goals.