A tool used to quantify process quality performance, this calculation transforms the number of defects identified in a production run or service delivery into a standardized rate representing the expected defects within one million opportunities. For example, if a manufacturing process produces 10 defects out of 10,000 units, this rate converts that figure into an estimation of how many defects would likely occur if one million units were produced under similar conditions.
This standardized metric allows for easy comparison of quality levels across different processes, product lines, or even entire organizations. Its adoption facilitates benchmarking against industry standards and supports continuous improvement initiatives by providing a clear, trackable quality target. The concept gained prominence alongside methodologies like Six Sigma, where minimizing process variation and defect rates is a core objective.