CPIM Practice Exam

Which type of cause is characterized by variations that affect everyone in a process?

1. Assignable causes

2. Common causes

3. Special causes

4. Temporary causes

The correct answer is: Common causes

The type of cause characterized by variations that affect everyone in a process is known as common causes. Common causes are inherent to the process itself and represent the natural variability that occurs in any system or process. This variability is typically consistent and predictable over time. In contrast to common causes, assignable causes refer to variations that can be traced to a specific source or event, affecting only certain instances of the process. Special causes are those variations that are not part of the process's normal behavior and often signal that something unusual has occurred, which can lead to significant impacts on quality or output. Temporary causes are typically not recognized as a standard category in quality control terminology, as they imply that their effects are not enduring in nature. Understanding the distinction between common and assignable causes is essential for process improvement as it helps organizations determine where to focus their efforts to reduce variability and improve performance. By addressing common causes, organizations can optimize their processes and minimize variation for everyone involved.