Stratification is a simple tool that examines the root cause of a problem by grouping data into specific groups or categories $($ Goetsch & Davis, $2021).$ ?It $$ s a quality improvement technique that divides data into subgroups based on certain characteristics. In the case of an amplifier assembly with three components from five vendors, stratification can help identify and address the root causes of the high reject rate. By analyzing reject rates within each vendor's components, the manufacturer can identify variations in reject rates, helping to pinpoint which vendors are contributing most to the high rate.

Stratification can help isolate component $-$ specific issues within each vendor stratum, allowing the manufacturer to understand if the rejection rate is primarily driven by problems with specific parts. Focusing on root causes can help narrow down potential issues, such as a specific vendor's manufacturing processes or a component's quality or specifications.

Stratification also allows for targeted corrective actions, addressing specific issues within each stratum, leading to more effective and efficient improvements. Continuous monitoring of reject rates within each stratum allows the manufacturer to assess the impact of implemented corrective actions, ensuring sustained improvements over time.

Applying stratification provides a more granular understanding of reject rates, allowing for targeted interventions and improvements. This systematic and data $-$ driven method facilitates a systematic and data $-$ driven method for identifying and addressing the root causes of the high reject rate in the amplifier assembly process.