SFD toolbox. Sustainable Sanitation Alliance, January 2017. An excreta flow diagram (also often described as shit flow diagram, SFD) is a tool to readily understand and communicate visualizing how excreta physically flows through a city or town. 
Here you can find out more about the SFD methods and tools. The guidance documents include:
- the Manual for SFD Production,
- the SFD calculation tool,
- the SFD master diagram and the SFD credibility process.
These are all currently under development and meanwhile the draft versions are available.
