Definition

    First Pass Yield(FPY)

    First Pass Yield (FPY) measures the percentage of units that pass through a process without rework or repair. It is a core quality metric for process capability and efficiency.

    What is First Pass Yield?

    FPY is calculated at the process step level to show how often units meet requirements the first time. It highlights hidden quality costs such as rework, scrap, and delays.

    Low FPY indicates process instability, insufficient controls, or upstream defects. High FPY indicates a stable process with strong prevention and detection controls.

    Key Points

    • FPY measures quality at each process step, not just final inspection
    • Low FPY drives hidden COPQ through rework and delays
    • Tracking FPY by process reveals bottlenecks and systemic weaknesses
    • Improving FPY often requires root cause analysis and control plan updates
    • FPY is a leading indicator of customer quality performance

    How to Calculate First Pass Yield

    Formula:

    FPY = (Units Passing Without Rework) / (Total Units Entering Process)

    Variables:

    • Units Passing Without Rework= Units that meet requirements on first pass
    • Total Units Entering Process= All units processed in the step

    Example:

    A line processes 1,000 units. 930 pass on first attempt, 70 require rework. FPY = 930 / 1,000 = 93%. If rework drops to 20 units, FPY improves to 98%.

    Implementation Guide

    Steps:

    1. 1Define FPY at each critical process step
    2. 2Capture pass/fail data at the point of inspection
    3. 3Trend FPY daily or weekly by product and line
    4. 4Identify low-FPY steps and analyze root causes
    5. 5Implement corrective actions and verify FPY improvement
    6. 6Update Control Plan and PFMEA based on findings

    Best Practices:

    • Use FPY in combination with final yield for full visibility
    • Separate first-pass defects from rework success rates
    • Normalize FPY by product family to avoid data masking
    • Review FPY in daily production meetings
    • Link FPY drops to immediate containment actions

    Common Mistakes to Avoid

    • • Counting reworked units as passing in FPY calculations
    • • Tracking only final yield and ignoring step-level FPY
    • • Not capturing FPY data in real time
    • • Failing to connect FPY losses to root cause analysis
    • • Ignoring FPY variation between shifts or suppliers

    Qualiteh's Approach to First Pass Yield

    Qualiteh integrates FPY tracking into daily quality dashboards and 8D workflows. We use FPY trends to prioritize corrective actions and quantify COPQ impact.

    Related Terms

    Copq
    Spc
    Fmea
    Root Cause Analysis
    8d Methodology

    Frequently Asked Questions

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