Which process is designed to proactively act before a problem occurs?

Common cause variation refers to the inherent fluctuations in a process that are natural and predictable. While understanding these variations is important for process improvement, this activity does not actively prevent problems before they occur; rather, it focuses on identifying and managing variations that are already part of the process.

Quality control involves monitoring and inspecting outputs during or after the production process to identify defects and ensure that products meet specified standards. This is a reactive approach, addressing problems only after they have occurred, rather than preventing them proactively as quality assurance does.

The Plan-Do-Check-Act (PDCA) cycle is a continuous improvement model that emphasizes iterative processes for enhancing performance. While it includes planning and checking stages to identify issues, it is not exclusively designed to prevent problems before they occur; instead, it provides a framework for ongoing improvement, which includes reacting to identified problems.