14 Visualizing quality control
This chapter covers
- Quality control measures
- Control charts for attributes (or qualitative data)
- Control charts for variables (or quantitative data)
Quality is a fundamental concept that permeates every aspect of our lives, from the products we use daily to the services we rely on. Defining quality, however, is not always straightforward. In a broad sense, quality can be understood as the degree to which a product or service meets or exceeds customer expectations. This encompasses attributes such as reliability, durability, and performance. But quality is not merely an attribute of a finished product; it is an integral aspect of the entire production and service delivery process. When organizations focus on quality, they aim to ensure that every component of their operations contributes to the creation of a superior final product or service.
To maintain and improve quality, organizations implement controls. Controls are systematic measures put in place to regulate processes, ensuring they function within defined parameters and produce consistent results. Controls can be preventive, aimed at stopping problems before they occur, or detective, identifying issues as they arise. Effective control mechanisms are essential for maintaining standards, reducing variability, and minimizing defects. Without proper controls, processes can deviate, leading to variations that compromise the quality of the final product.