How are defects defined within a system?

Defects within a system are defined as variability because they represent deviations from the expected or desired output. When a system operates effectively, it produces consistent outputs that meet predefined standards or quality metrics. However, when variability occurs — whether it's in product performance, service delivery, or process execution — it indicates a defect in the system. This can arise from various factors such as miscommunication, procedural errors, or equipment malfunctions, leading to variations that do not conform to quality benchmarks.

In the context of quality management and process improvement, identifying and reducing this variability is essential for enhancing overall system performance and achieving consistency in outputs. Rather than viewing defects as improvements, necessary adjustments, or consistent outputs, they are fundamentally about the inconsistencies that disrupt the desired function or quality. Therefore, recognizing defects as variability allows organizations to target the root causes of these issues and implement effective strategies for quality enhancement.