The central challenge this project tackled was how to design and deploy an effective Immunization Information System (IIS) in Pakistan that worked for both the bureaucratic system and the vaccinators on the ground. On one side, policy makers wanted real-time monitoring, accountability, and reliable data to improve immunization coverage; on the other, vaccinators—often with low technical literacy and heavy workloads—struggled with duplicative paper and digital recordkeeping, unreliable internet connectivity in rural areas, and fear of sharing critical feedback due to job repercussions. These tensions created deep usability and trust barriers: supervisors pushed for top-down monitoring features, while vaccinators needed tools that reduced effort, worked offline, and aligned with their field realities. The iterative design process revealed that the challenge was not just building a technical system, but reconciling conflicting priorities, validating genuine user needs, and ensuring that end users felt safe and empowered to participate in shaping the tool that directly affected their daily work. 

The study used a multi-method, user-centered approach to design and evaluate the system. The researchers conducted participant observation, semi-structured interviews with over 100 vaccinators, mothers, and health workers, surveys with 50 vaccinators, and content analysis of government documents. They also attended more than 30 meetings with senior bureaucrats in the health sector and ran at least 10 focus groups, trainings, and usability testing sessions with vaccinators across multiple districts in Punjab. 

An iterative prototyping process was followed: early versions of the app were tested in the field, redesigned based on feedback, and re-evaluated through task-based assessments where vaccinators registered children using the app and NFC cards under observation. Quantitative measures such as task completion time and error rates were collected, alongside qualitative feedback on likes, dislikes, and suggested improvements. This mixed set of methods ensured that the design responded both to the practical realities of vaccinators in the field and to the administrative needs of policymakers.