CPIM Practice Exam

What is the primary characteristic of an assignable cause compared to a common cause?

1. It is larger in magnitude and can be easily identified

2. It affects every outcome predictably

3. It is a minor influence on process outcomes

4. It occurs infrequently and is not consistently repeatable

The correct answer is: It is larger in magnitude and can be easily identified

The primary characteristic of an assignable cause is that it occurs infrequently and is not consistently repeatable. Assignable causes are specific, identifiable factors that can lead to variations in a process, differentiating them clearly from common causes, which represent the inherent variability always present in a system. Assignable causes are usually tied to specific events or conditions that can lead to unusual outcomes. These could be machine failures, human errors, or changes in materials or methods that happen occasionally. Unlike common causes, which contribute to ongoing fluctuations in process outputs predictably and consistently, assignable causes result in unexpected or atypical deviations that can be traced back to specific instances. This distinction is critical in quality control and process improvement because it implies that with the right analysis, processes can be adjusted to mitigate the effects of assignable causes, leading to better overall performance. Recognizing and addressing assignable causes allows organizations to enhance their processes and consistently meet quality standards.