In manufacturing and quality control, one important number is PPM.
PPM means Parts Per Million. It tells us how many defective parts are found in one million parts produced.
Many teams only look at rejection percentage. But percentage can be misleading when production quantity is very high. PPM gives a clearer and more accurate picture of quality performance.
What is PPM?
PPM shows how many parts are defective out of 10,00,000 (one million) parts.
PPM = defects in one million parts
Lower PPM means better quality.
Higher PPM means more defects in the process.
Why PPM is Important?
PPM is widely used in production and quality because:
It gives a standard way to measure defects
It helps compare performance between lines or plants
It shows small problems clearly
Customers often ask for PPM targets
It supports continuous improvement
World-class companies usually target very low PPM.
PPM Formula
PPM is calculated using this formula:
PPM = (Defective Parts ÷ Total Parts Produced) × 10,00,000
Simple Example
Suppose in one day:
Total production = 80,000 parts
Rejected parts = 16
Now calculate:
PPM = (16 ÷ 80,000) × 10,00,000
PPM = 200
👉 Out of every 10 lakh parts, about 200 parts are defective.
Final Thoughts
PPM is the real quality number that shows the true health of your process. Even when rejection percentage looks small, PPM may reveal hidden quality problems. That is why strong production and quality teams always monitor PPM closely.
Remember:
✔ Lower PPM = Better quality
✔ Higher PPM = Need improvement
