A collection of circular SVG icons encodes Statistical Process Control (SPC) states, including pass, fail, erratic, random, and high/low variation outcomes. Each icon combines a colored ring, a letter label, and a simple line chart rendered with D3’s `line` and `curveBasis` functions. React components compose reusable elements like borders, target lines, and plot lines, with props for width, height, and performance (improvement or concern) that adjust stroke colors dynamically. The icons are displayed in a responsive flex layout.