Six Sigma Green Belt Certification Practice Exam

What type of variation in a process can be addressed by Six Sigma methodologies?

1. Common cause variation

2. Special cause variation

3. Both common and special cause variation

4. Insignificant variation

The correct answer is: Both common and special cause variation

Six Sigma methodologies are designed to improve process quality by systematically identifying and eliminating both common cause and special cause variation. Common cause variation refers to the inherent variability that is always present in a process due to the system and its normal functioning. This type of variation is generally predictable and stable over time. On the other hand, special cause variation arises from specific, identifiable factors that lead to deviation from the typical process behavior; it is often unexpected and can indicate issues that need to be addressed. By focusing on both types of variation, Six Sigma enables organizations to improve processes comprehensively, ensuring that the overall stability and capability of the process are enhanced. This dual focus is key to achieving significant quality improvements and driving operational excellence. Addressing both forms of variation leads to a robust process that meets customer requirements effectively and efficiently. The other options focus on only one type of variation or are not relevant to the comprehensive approach that Six Sigma embodies.