Bullet Chart

Introduction to Bullet Charts

A Bullet Chart is a linear chart type originally designed by data visualization expert Stephen Few as a more compact and information-rich alternative to traditional dashboard gauges. Bullet charts can simultaneously display actual values, target values, and performance ranges within a limited space, clearly showing the completion rate and performance status through comparison.

The design philosophy of bullet charts is to maximize the data-ink ratio, displaying the most useful information in the smallest space, making them particularly suitable for dashboard and performance monitoring scenarios.

English Names: Bullet Chart

Other Names: Progress Bar Chart, Target Comparison Chart, Bullet Graph

Components of a Bullet Chart

Basic Bullet Chart

Chart Type	Bullet Chart
Suitable Data	One categorical data field, one continuous data field (actual value), one target value, optional performance ranges
Functionality	Display comparison between actual and target values, evaluate performance levels
Data Mapping	Categorical data field maps to vertical axis position Continuous data field maps to bar length Target value maps to marker line Performance ranges map to background color bands
Data Size Limit	Single or multiple indicators, recommended not to exceed 10

The main components of a bullet chart include:

Actual Value Bar: Represented by a thick, dark-colored bar showing the current actual achieved value
Target Value Marker: Represented by a vertical line or other marker, indicating the target to be achieved
Performance Ranges: Background uses color bands of different shades, typically divided into poor, good, and excellent ranges
Scale Axis: Provides numerical reference to help readers understand specific numerical values

import { Chart } from '@antv/g2';

const chart = new Chart({
  container: 'container',
  theme: 'classic',
});

const data = [
  {
    title: 'Sales Completion Rate',
    ranges: 100,
    measures: 80,
    target: 85,
  },
];

chart.options({
  type: 'view',
  coordinate: { transform: [{ type: 'transpose' }] },
  children: [
    {
      type: 'interval',
      data,
      encode: { x: 'title', y: 'ranges', color: '#f0efff' },
      style: { maxWidth: 30 },
      axis: {
        y: {
          grid: true,
          gridLineWidth: 2,
          title: 'Completion Rate (%)',
        },
        x: {
          title: false,
        },
      },
    },
    {
      type: 'interval',
      data,
      encode: { x: 'title', y: 'measures', color: '#5B8FF9' },
      style: { maxWidth: 20 },
      label: {
        text: 'measures',
        position: 'right',
        textAlign: 'left',
        dx: 5,
        formatter: (d) => `${d}%`,
      },
    },
    {
      type: 'point',
      data,
      encode: {
        x: 'title',
        y: 'target',
        shape: 'line',
        color: '#3D76DD',
        size: 8,
      },
      tooltip: {
        title: false,
        items: [
          {
            channel: 'y',
            name: 'Target Value',
            valueFormatter: (d) => `${d}%`,
          },
        ],
      },
    },
  ],
});

chart.render();

Use Cases for Bullet Charts

Appropriate Use Cases

Scenario 1: Performance Indicator Monitoring

Bullet charts are ideal tools for displaying performance indicator completion status, clearly comparing actual performance with target requirements.

import { Chart } from '@antv/g2';

const chart = new Chart({
  container: 'container',
  theme: 'classic',
});

const colors = {
  ranges: ['#ffebee', '#fff3e0', '#e8f5e8'],
  measures: '#1890ff',
  target: '#ff4d4f',
};

// Transform data structure
const transformedData = [
  { title: 'Project Progress', value: 40, level: 'Poor' },
  { title: 'Project Progress', value: 30, level: 'Good' },
  { title: 'Project Progress', value: 30, level: 'Excellent' },
];

const data = [
  { title: 'Project Progress', value: 60, type: 'Actual Progress' },
  { title: 'Project Progress', value: 80, type: 'Target Progress' },
];

chart.options({
  type: 'view',
  coordinate: { transform: [{ type: 'transpose' }] },
  children: [
    {
      type: 'interval',
      data: transformedData,
      encode: { x: 'title', y: 'value', color: 'level' },
      transform: [{ type: 'stackY' }],
      scale: {
        color: {
          domain: ['Poor', 'Good', 'Excellent'],
          range: colors.ranges,
        },
      },
      style: { maxWidth: 30 },
    },
    {
      type: 'interval',
      data: {
        value: data,
        transform: [
          { type: 'filter', callback: (d) => d.type === 'Actual Progress' },
        ],
      },
      encode: { x: 'title', y: 'value', color: colors.measures },
      style: { maxWidth: 16 },
    },
    {
      type: 'point',
      data: {
        value: data,
        transform: [
          { type: 'filter', callback: (d) => d.type === 'Target Progress' },
        ],
      },
      encode: {
        x: 'title',
        y: 'value',
        shape: 'line',
        color: colors.target,
        size: 8,
      },
      axis: { y: { grid: true, title: 'Progress (%)' }, x: { title: false } },
    },
  ],
});
chart.render();

Scenario 2: Budget Execution Tracking

Bullet charts can effectively display budget execution status, including actual expenditure, budget targets, and warning ranges.

Scenario 3: Resource Utilization Monitoring

Through bullet charts, you can intuitively understand the usage of various resources and identify overused or underutilized resources.

import { Chart } from '@antv/g2';

const chart = new Chart({
  container: 'container',
  theme: 'classic',
});

const resourceData = [
  {
    resource: 'CPU Usage',
    ranges: 100,
    measures: 65,
    target: 80,
  },
  {
    resource: 'Memory Usage',
    ranges: 100,
    measures: 45,
    target: 70,
  },
  {
    resource: 'Disk Usage',
    ranges: 100,
    measures: 88,
    target: 85,
  },
  {
    resource: 'Network Bandwidth',
    ranges: 100,
    measures: 72,
    target: 75,
  },
];

chart.options({
  type: 'view',
  coordinate: { transform: [{ type: 'transpose' }] },
  children: [
    {
      type: 'interval',
      data: resourceData,
      encode: { x: 'resource', y: 'ranges', color: '#f5f5f5' },
      style: { maxWidth: 30 },
    },
    {
      type: 'interval',
      data: resourceData,
      encode: {
        x: 'resource',
        y: 'measures',
        color: (d) => (d.measures > d.target ? '#ff7875' : '#52c41a'),
      },
      style: { maxWidth: 20 },
      label: {
        text: 'measures',
        position: 'right',
        textAlign: 'left',
        dx: 5,
        formatter: (d) => `${d}%`,
      },
    },
    {
      type: 'point',
      data: resourceData,
      encode: {
        x: 'resource',
        y: 'target',
        shape: 'line',
        color: '#1890ff',
        size: 6,
      },
      axis: {
        y: {
          grid: true,
          title: 'Usage Rate (%)',
        },
        x: {
          title: 'System Resources',
        },
      },
    },
  ],
});

chart.render();

Inappropriate Use Cases

Scenario 1: Time Trend Analysis

Bullet charts primarily display status comparisons at a specific point in time and are not suitable for showing trends over time. Line charts should be used in such cases.

Scenario 2: Part-to-Whole Relationships

If you need to show the proportional relationship of parts to the whole, pie charts or donut charts are more appropriate.

Scenario 3: Large Data Volume

When displaying a large number of indicators, bullet charts can cause visual confusion. It’s recommended to use grouped displays or other chart types.

Extensions of Bullet Charts

Multi-dimensional Bullet Charts

Display the performance of multiple related indicators through grouping, facilitating horizontal comparison.

import { Chart } from '@antv/g2';

const chart = new Chart({
  container: 'container',
  theme: 'classic',
});

const multiData = [
  {
    department: 'Sales',
    indicator: 'Sales Revenue',
    ranges: 100,
    measures: 85,
    target: 90,
  },
  {
    department: 'Sales',
    indicator: 'Customer Count',
    ranges: 100,
    measures: 92,
    target: 85,
  },
  {
    department: 'Marketing',
    indicator: 'Brand Awareness',
    ranges: 100,
    measures: 78,
    target: 80,
  },
  {
    department: 'Marketing',
    indicator: 'Marketing ROI',
    ranges: 100,
    measures: 88,
    target: 85,
  },
];

chart.options({
  type: 'view',
  coordinate: { transform: [{ type: 'transpose' }] },
  children: [
    {
      type: 'interval',
      data: multiData,
      encode: { x: 'indicator', y: 'ranges', color: '#f0f0f0' },
      style: { maxWidth: 30 },
    },
    {
      type: 'interval',
      data: multiData,
      encode: { x: 'indicator', y: 'measures', color: 'department' },
      style: { maxWidth: 20 },
      label: {
        text: 'measures',
        position: 'right',
        textAlign: 'left',
        dx: 5,
      },
    },
    {
      type: 'point',
      data: multiData,
      encode: {
        x: 'indicator',
        y: 'target',
        shape: 'line',
        color: '#666',
        size: 6,
      },
      axis: {
        y: {
          grid: true,
          title: 'Completion Rate',
        },
        x: {
          title: 'Key Indicators',
        },
      },
    },
  ],
});

chart.render();

Layered Performance Ranges

Provide more detailed performance evaluation criteria through background ranges of different color shades.

import { Chart } from '@antv/g2';

const chart = new Chart({
  container: 'container',
  theme: 'classic',
});

const colors = {
  ranges: ['#ffebee', '#fff3e0', '#e8f5e8'],
  measures: '#1890ff',
  target: '#ff4d4f',
};

// Transform data structure
const transformedData = [
  { title: 'Project Progress', value: 40, level: 'Poor' },
  { title: 'Project Progress', value: 30, level: 'Good' },
  { title: 'Project Progress', value: 30, level: 'Excellent' },
];

const data = [
  { title: 'Project Progress', value: 60, type: 'Actual Progress' },
  { title: 'Project Progress', value: 80, type: 'Target Progress' },
];

chart.options({
  type: 'view',
  coordinate: { transform: [{ type: 'transpose' }] },
  children: [
    {
      type: 'interval',
      data: transformedData,
      encode: { x: 'title', y: 'value', color: 'level' },
      transform: [{ type: 'stackY' }],
      scale: {
        color: {
          domain: ['Poor', 'Good', 'Excellent'],
          range: colors.ranges,
        },
      },
      style: { maxWidth: 30 },
    },
    {
      type: 'interval',
      data: {
        value: data,
        transform: [
          { type: 'filter', callback: (d) => d.type === 'Actual Progress' },
        ],
      },
      encode: { x: 'title', y: 'value', color: colors.measures },
      style: { maxWidth: 16 },
    },
    {
      type: 'point',
      data: {
        value: data,
        transform: [
          { type: 'filter', callback: (d) => d.type === 'Target Progress' },
        ],
      },
      encode: {
        x: 'title',
        y: 'value',
        shape: 'line',
        color: colors.target,
        size: 8,
      },
      axis: { y: { grid: true, title: 'Progress (%)' }, x: { title: false } },
    },
  ],
});
chart.render();

Vertical Bullet Charts

When space is limited or special layouts are needed, vertical bullet charts can be used.

import { Chart } from '@antv/g2';

const chart = new Chart({
  container: 'container',
  theme: 'classic',
});

const verticalData = [
  {
    metric: 'Q1 Sales',
    ranges: 100,
    measures: 80,
    target: 85,
  },
  {
    metric: 'Q2 Sales',
    ranges: 100,
    measures: 92,
    target: 88,
  },
  {
    metric: 'Q3 Sales',
    ranges: 100,
    measures: 76,
    target: 90,
  },
];

chart.options({
  type: 'view',
  children: [
    {
      type: 'interval',
      data: verticalData,
      encode: { x: 'metric', y: 'ranges', color: '#f0f0f0' },
      style: { maxWidth: 30 },
    },
    {
      type: 'interval',
      data: verticalData,
      encode: { x: 'metric', y: 'measures', color: '#52c41a' },
      style: { maxWidth: 20 },
      label: {
        text: 'measures',
        position: 'top',
        textAlign: 'center',
        dy: -5,
      },
    },
    {
      type: 'point',
      data: verticalData,
      encode: {
        x: 'metric',
        y: 'target',
        shape: 'line',
        color: '#ff4d4f',
        size: 6,
      },
      axis: {
        y: {
          grid: true,
          title: 'Sales (10k CNY)',
        },
        x: {
          title: 'Quarter',
        },
      },
    },
  ],
});

chart.render();

Comparison with Other Charts

Bullet Chart vs Bar Chart

Bullet charts add target values and performance ranges to bar charts, providing richer comparison dimensions
Bar charts are mainly used to compare numerical values across different categories, while bullet charts focus on comparing actual values with target values

Bullet Chart vs Gauge Chart

Bullet charts save more space than gauge charts and can display more information in the same space
Gauge charts more intuitively display the status of a single indicator, while bullet charts are more suitable for multi-indicator comparison

Bullet Chart vs Progress Chart

Bullet charts provide more contextual information, including target values and performance ranges
Progress charts mainly show completion progress, while bullet charts can show the quality of performance