Case Study: SEVA

Pictured: Mobile app inside one of the sanitation units.

Pictured: Mobile app inside one of the sanitation units.

This project covers the iterative design + testing process of an on-demand maintenance application for Caltech's onsite wastewater treatment technology.






  • Cody Finke (Lead Developer/Investigator)
  • Michael Hoffmann (Principal Investigator)
  • Clément Cid (Investigator)
  • Anastasia Hanan (Design + Research)


Our target user is a non-engineer in India that may have low levels of technical expertise and/or literacy.


Funding Partners

  • Bill and Melinda Gates Foundation
  • Vodafone
  • Disney R&D

Project Outcomes



Timeline of the project:

The larger body of work has focused on both a US and an Indian Market (for ease of navigation, this project mostly focuses on India and 2017's app design + testing).


Initial Research:

(see full report at the end of project)


Key Findings:

  1. Our tech will only be successful if we can also provide a maintenance plan.

  2. Low cost maintenance may require building information for users with low technical skill and diverse literacy rates.

  3. The greatest challenge for design will be around identifying parts (pictures and parts may update independently) and information design for over 122 languages in India.




App design + user testing process overview:


V1 design:

Guiding design constraints from secondary research

Decisions Made:

  • Material design aesthetics for simplicity, longevity, and android majority
  • Images not video for data usage
  • Symbols match IRL parts to in APP images



V1 User Testing:


On site interviews (in sanitation units) with partners in two locations near Coimbatore, India.
Beta prototype in Invision.
Translator fo non-English speakers.

Main goal:

Can users complete the basic flow?


V2 Design:


V2 User Testing:


Remote user testing. We did initial testing via, but felt that users were too "trained" (we got too positive of responses). As an alternative, we instead sourced participants ourselves and completed testing using

Main goal:

Testing navigation through information architecture by asking users to complete tasks.


V3 APP Design:



Ethnographic Research

Phase 1 was completed in 2014 and helped inform app design above


Phase 1 Design Informed by Ethnography:

©anastasiahanan 2017