Prozessfähigkeitsbewertungen

Prozessfähigkeit refers to the statistical measure of a manufacturing or business process's ability to consistently produce output that meets specified requirements. It quantifies how well a process is centered within the tolerance limits of a specification and how much variation it exhibits. A process is considered "capable" if its inherent variability is small enough to remain within the defined upper and lower specification limits.

The concept is typically evaluated using process capability indices, such as Cp and Cpk. The Cp index measures the potential capability of a process, assuming it is centered within the tolerance limits. It compares the width of the specification tolerance to the width of the process spread (typically three times the standard deviation). A higher Cp value indicates a potentially more capable process.

The Cpk index, on the other hand, considers the actual centering of the process. It is the minimum of the capability indices calculated for the upper and lower specification limits, taking into account the process mean's deviation from the target value. A Cpk value greater than or equal to 1.33 is often considered a benchmark for a capable process, though this can vary by industry.

Analyzing process capability is crucial for quality control and continuous improvement. It helps identify processes that are not performing as expected, allowing for targeted interventions to reduce variation or improve centering. This leads to reduced waste, improved product quality, and increased customer satisfaction. Understanding and monitoring process capability is a fundamental aspect of statistical process control (SPC).