Other tools have been developed that also explore the flows of faecal waste through the sanitation service chain. These include:

• The Faecal Waste Flow Calculator, developed by the IRC (www.ircwash.org/tools/faecal-waste-flow-calculator), approximates shit flow volumes along the sanitation service chain. As mentioned in FAQ 5, numerous assumptions are required when converting the percentage of the population’s excreta to volumes and we recommend caution.
• The Performance Assessment System (PAS) for urban water supply and sanitation developed by CEPT University (www.pas.org.in). This tool is based on a questionnaire which is filled in for a city or town to assess performance indicators on water, sanitation, and solid waste management. It then identifies key strengths and areas for improvement.