What percentage does Deming attribute to common causes in a management system?

Deming attributed a significant portion of variation in a management system to common causes, which are inherent in the process and cannot be eliminated by simple fixes. According to his philosophy, approximately 94% of the variation in quality and performance can be traced back to these common causes, implying that issues typically arise from the system itself rather than external factors or special causes.

Recognizing that only a small percentage, about 6%, is attributed to special causes, emphasizes the importance of focusing on systemic improvements rather than merely addressing the symptoms of problems. Systems thinking is critical in Six Sigma as it prioritizes understanding how processes function overall, and this substantial percentage comparison serves to highlight the importance of long-term solutions in management practices to reduce variability and improve quality.

The other options propose different proportions which do not accurately reflect Deming's views regarding the makeup of variation in a management system. Each of those percentages suggests varying levels of importance placed on common versus special causes, which diverges from the foundational philosophy Deming presented in his work.