Mismanufactured

Mismanufactured is an adjective used to describe products or components produced in a manufacturing process that do not meet defined specifications or design intent. It denotes nondisforming items that fail to satisfy quality requirements due to errors in design transfer, process execution, or inspection.

Causes of mismanufacturing include human error, equipment malfunction, tool wear, incorrect processing parameters, material variability, inadequate process control, and poor supplier quality. Complex assemblies and tight tolerances increase the likelihood of mismanufactured outputs, especially when rapid production or changeovers introduce instability into the process.

Mismanufactured items can be categorized by impact: functional, cosmetic, dimensional, or safety-critical failures. Examples include misdrilled holes, incorrect thread profiles, parts out of tolerance, missing features, surface defects, or components with inadequate heat treatment or coatings.

Detection and disposition rely on quality assurance and product inspection. Methods include statistical process control, sampling plans, nondestructive testing, and automated sensors. When identified, mismanufactured items are typically quarantined and dispositioned as rework, repair, acceptance at reduced parameters, or scrap, depending on risk and feasibility.

Prevention focuses on robust design and process control. Practices include design for manufacturability, process capability analysis (Cp, Cpk), error-proofing (poka-yoke), standardized work, preventive maintenance, calibration, and supplier quality management. Effective traceability and change management reduce recurrence and support recalls if necessary.

Mismanufactured products have economic and regulatory implications, including waste, rework costs, downtime, recalls, and potential liability. In regulated sectors such as aerospace, medical devices, and automotive, nonconforming parts require strict documentation and traceability to ensure safety and compliance.