Sankey diagrams are used to indicate a flow of resources. In a business scenario they might be used to illustrate the flow of money, or in a manufacturing environment, the flow of materials. They have been around since the start of the 20th century and were first used in engineering applications.
Commercial software tools which support Sankey diagrams include:
e/Sankey – primarily used for drawing cost, material and energy flows. Supports several European languages, export to various graphics formats, a live link to Excel and a highly functional diagram editor.
S-Draw – has been used to visualize money flows, call centre activity, manufacturing material flows and several other business applications. Provides access to Excel, Access, SQL Server and other data sources.
Freeware and Open Source include:
Fineo – an online tool for creating Sankey type diagrams. Very sophisticated tool.
Parallel Sets – implements top down bands with data imported from csv files. Runs on Windows, Mac and Linux.
Sankey Helper – a set of macros to draw Sankey diagrams in Excel.