Offspec

Off-spec, short for off specification, is a quality term describing goods that do not meet defined product specifications. It applies to raw materials, in-process materials, and finished products across many industries, including manufacturing, pharmaceuticals, food and beverage, and electronics. An off-spec item may be rejected, reworked, reprocessed, salvaged, or disposed, depending on the nature of the deviation, its magnitude, economic considerations, and regulatory requirements. It is distinct from in-spec products and from “out of spec” variations observed during testing.

Causes include process drift, improper calibration, equipment failure, variability in raw materials, contamination, measurement or sampling errors, and changes in environmental conditions. Deviations can be classified by severity or by whether the specification limit is exceeded on one side (unidirectional) or both.

Handling usually involves quarantine or segregation of the material, label with deviation notes, and documentation for traceability. Disposition decisions follow a deviation or nonconformance procedure and may include rework to bring material into specification, reprocessing, blending, reclaiming, or scrap. In regulated industries, off-spec results initiate batch records investigations, root-cause analysis, and corrective and preventive actions (CAPA).

Quality systems often aim to minimize off-spec production using statistical process control, control charts, and process capability indices (Cp, Cpk). Suppliers and manufacturers may implement specifications, supplier quality agreements, and acceptance criteria to prevent or quickly detect off-spec material.

Impact includes potential cost increases from waste, rework, and recalls, as well as effects on customer satisfaction and regulatory compliance. The term is widely used in manufacturing to indicate deviation from defined standards rather than just a temporary measurement fluctuation.