Quality Analytics: Tracking First-Pass Yield and Rejection Trends in Real Time

First-Pass Yield vs Final Yield

Final yield is the percentage of good parts shipped. First-pass yield (FPY) is the percentage that pass quality checks without any rework. A factory with 98% final yield might have 85% FPY — meaning 13% of all parts required rework before shipping. Rework cost is often invisible because it is buried in labour costs.

Real-Time SPC Charts

Statistical Process Control (SPC) charts plot quality measurements over time and flag when a process goes out of control — before it starts producing defects. Connect your measurement equipment (gauges, vision systems, test benches) to your quality dashboard. Display Xbar-R charts, track Cpk, and alert operators when trends indicate drift.

Pareto Analysis of Rejection Reasons

The Pareto principle says 20% of defect types cause 80% of rejections. A real-time Pareto chart of rejection reasons — updated every shift — focuses improvement effort on the highest-impact problems. Display it on a screen at the quality gate where operators enter rejection reasons.

Correlating Quality with Machine Parameters

Once you have both quality data and machine parameter data, you can correlate them. Does rejection rate spike when spindle temperature exceeds 65°C? Does FPY drop when the same operator runs a specific machine on night shift? These correlations reveal root causes that manual analysis never finds.