Veamäära

Veamäära is an Estonian term used in quality management and reliability engineering to denote the defect rate—the share of products or components that fail to meet quality specifications within a defined batch, lot, or time period. The word is formed from vea, meaning defect or fault, and määr, meaning rate or measure, so veamäärä literally translates to defect rate.

Definition and usage

Veamäära represents the ratio of defective units to the total number of units inspected or produced. It is commonly expressed as a percentage or in parts per million (ppm). It is distinct from metrics that describe time-based reliability, such as failure rate, because veamäära focuses on defects detected during inspection or testing rather than the time a product operates before failure.

Calculation and data

Veamäära = D / N, where D is the number of defective items and N is the total inspected items. In production environments, the denominator may be the batch size or the number of items within a sampling plan. Data sources include incoming inspections, in-process checks, final testing, and quality audits. Defects are often categorized by severity or type (major vs. minor) to support prioritization and improvement efforts.

Applications and implications

Veamäära is used to monitor process quality, evaluate supplier performance, guide process improvement initiatives (such as Six Sigma projects), and inform acceptance sampling decisions. A rising veamäära signals potential process drift or quality issues, while a declining rate indicates effective corrective actions.

Limitations

The measure depends on the inspection regime and defect definitions. It may not capture latent defects or customer-perceived quality if inspection coverage is incomplete. Consistent definitions and sampling methods are essential for meaningful comparisons over time or across processes.