Sankey
A Sankey Chart is a type of flow diagram used to represent the movement of data, resources, or values between different stages of a process. The width of each arrow (or flow line) corresponds to the size of the flow, making it easy to visualize proportions, relationships, and distribution patterns within complex systems.
Sankey charts are especially useful for highlighting bottlenecks, inefficiencies, and flow distribution, whether in processes, customer journeys, or energy/resource usage.
Best Situations to Use
Use a Sankey chart when you want to:
Visualize the flow of data or resources across different process stages.
Track the distribution of energy, materials, or finances in a system.
Map customer journeys across multiple touchpoints.
Identify inefficiencies or waste in business or operational systems.
Communicate complex interconnected processes in a simple, intuitive way.
Example: An energy analyst can use a Sankey chart to visualize how energy flows through various components of a manufacturing plant. By analyzing where flows narrow or dissipate, inefficiencies and waste points become immediately visible.
Variations
Several variations of the Sankey chart are available:
Multi-level Sankey Chart: Adds multiple layers of nodes to show deeper sub-processes.
Circular Sankey Chart: Places nodes and flows in a circular layout, ideal for cyclic or feedback loops.
Marimekko (Mekko) Chart: Combines bar chart and Sankey concepts, using variable-width bars instead of flows.
Interactive Sankey Chart: Supports interactive filtering and highlighting for deeper analysis.
Stacked Sankey Chart: Displays multiple sub-flows within the same node to show distribution breakdowns.
Properties of the Sankey Chart
General
Component Name: Unique identifier for the chart.
Left / Top: Position of the chart on the canvas.
Height / Width: Chart dimensions.
Initial Visibility: Toggle chart visibility at load.
Max Button: Enable maximize functionality.
Animation: Enable animated rendering.
Edge Color Style: Define edge style (e.g., Gradient, Source-based, Target-based).
Highlight Path Style: Choose highlight type (e.g., Adjacent, Trajectory).
Background
Gradient Rotation: Adjust gradient angle.
Opacity: Control transparency.
Gradient: Define gradient type and direction; add multiple colors.
Border / Color / Radius: Customize chart borders.
Shadow / Color / Transparency: Add and adjust shadow effects.
Node Style
Random Node Color: Assign random colors to nodes.
Label Customization: Configure font color, size, style, weight, family.
Level Colors: Assign distinct colors for each node level.
Line Opacity: Adjust connector line transparency.
Node Gap: Define spacing between nodes.
Show Percent Value: Display percentage values inside nodes.
Text Align: Align labels within nodes (left, right, top, bottom).
Tooltip
Show Tool Tip: Enable/disable tooltip display.
Configuration:
Background Color, Border Color, Font Color.
Font Size, Style, Weight, Family.
Box Width, Precision (decimal places).
Title & Sub-Title
Show Title Box: Toggle visibility of title container.
Title Settings: Font color, size, style, weight, alignment, family, decoration.
Title Bar Height: Adjust height.
Description: Add explanatory text under title.
Dataset Description: Auto-populate from dataset mapping.
Sub-Title: Similar settings for font, style, alignment, and decoration.
Formatter
Unit: Define measurement unit.
Precision: Set decimal places.
Currency: Apply currency formatting.
Position: Place unit/currency before or after numbers.
Number Formatter: Choose Indian or International style.
Export Options
Context Menu: Enable right-click export options in preview.
Supported Formats: Excel (.xlsx), CSV (.csv), JPEG (.jpg), PNG (.png), PPTX (.pptx), PDF (.pdf).
Print Option: Print chart directly.
Export Metadata: Add custom heading, subheading, and filename.
Global Export Type: Define default export type (Screenshot / Tabular).
Dataset Properties
When configuring a Sankey chart:
Source Field: Define the origin node.
Target Field: Define the destination node.
Value Field: Define the flow magnitude between nodes.
Additional options:
Category-based Coloring: Assign colors by source or target category.
Conditional Colors: Apply rules to value fields using indicators.
Example
Using the sample dataset:
Source: Department A
Target: Department B, C, D
Value: Resource allocation values
The Sankey chart displays how resources from Department A flow into multiple departments, with arrow thickness showing the proportion allocated.