Designing in quality through design control: a manufacturer's perspective.

Quality by design is a comprehensive program that begins with understanding user needs and continues through (but does not end with) monitoring customer acceptance. Management tools and processes such as ISO 9000 standards and the Food and Drug Administration Quality System Regulations exist to guide medical device manufacturers in quality practices. The goal is to deliver products acceptable for their intended use. Quality control begins with defining attributes ranging from color to accuracy and precision. Failure mode and effects analysis and risk analysis consider both probability and severity of potential malfunctions and their effects on patients or operators. Tools used to implement design and production practices include Program Evaluation and Review Technique (PERT) charts and industry-conceived concepts, such as Six Sigma techniques. Their use varies with manufacturer, depending on product and customer needs and the manufacturer's specific quality practices. Verification confirms that input goals are met. Then, validation assures that intended clinical needs are continually satisfied by establishing adequate production specifications. Conformance is monitored to verify that stable, consistent processes are in place, and precise user instructions enable the device to satisfy its intended use. Finally, complaint tracking can help assess whether needs have been met. Modifications in service, hardware, or instructions (including quality control) might be required. Therefore, both manufacturers and users work in partnership for continual improvement. The manufacturer's knowledge of design, production, and service needs of its devices enable it to recommend appropriate quality-control protocols for clinical testing.