A field inspection app for railway signaling that works completely offline.

Indian Railways SMMS mobile app gives field technicians offline maintenance forms, live station maps, and equipment failure reports on Android devices.

Project Context & Overview

Signaling equipment keeps trains running safely. Indian Railways maintenance teams inspect track circuits, signals, and point machines daily. Because railway tracks often run through dead zones with no mobile reception, paper forms were previously used. We built the SMMS Flutter app to let technicians complete full inspection checklists on site with automatic sync once back online.

Engineering Challenges

Field workers frequently lose cellular reception along track routes, meaning the app could never depend on an active internet connection to save data.
Different equipment types require different inspection questions and checks, so the forms needed to render dynamically based on equipment type.
Supervisors needed to view equipment issues across railway stations on a visual map without lag.

Key Architectural Contributions

[01] Map Integration with Geoserver

Connected Geoserver map endpoints to display railway stations visually. Clicking any station marker opens a smooth slide window showing equipment status, similar to Google Maps.

[02] Offline-First Data Storage

Stored all pending inspection entries locally in SQLite. The app monitors network status and uploads queued inspections as soon as Wi-Fi or cellular data returns.

[03] Interactive Drill-down Charts

Built bar, line, and pie charts for failure analytics. Tapping any chart opens a secondary chart with granular sub-category details.

[04] Dynamic Form Fields

Wrote form generators that load custom input fields depending on whether a technician is inspecting an LED signal, battery bank, or point machine.

Delivered Artifacts

Complete Flutter mobile application for Android field devices
Geoserver GIS map interface with interactive marker sliders
Robust offline-to-online reconciliation engine
Dynamic multi-tier inspection report and charting module

About the Author

Kartik Butani is a Senior Software Engineer specializing in scalable NestJS backends, React/Next.js platforms, PostGIS spatial data, and enterprise architectures.