In Six Sigma, how is a defect defined?

In Six Sigma, a defect is defined as any instance where a product fails to meet customer requirements. This definition is centered on the customer's perspective and emphasizes that quality is measured by the satisfaction of customer needs and expectations. In this context, a defect signifies a failure to deliver on these requirements, which can lead to dissatisfaction or a negative impact on the customer experience.

Understanding this definition is crucial in Six Sigma methodologies, as the ultimate aim is to improve processes to enhance product quality and reduce variations that can lead to such defects. This focus on customer requirements highlights the importance of understanding what the customer values and expects from a product, ensuring that all aspects of the production and service processes are aligned with these expectations.

The other options do not accurately reflect the essence of defect measurement in Six Sigma. Measurements below a preset standard or specifications do not necessarily correlate with the satisfaction or requirements of the customer, and stating that a defect means a product meets customer needs is contradictory to the definition of a defect itself. Therefore, defining a defect in the context of customer requirements allows for a clearer understanding of quality and process improvement goals in Six Sigma initiatives.