A mobile Occupational Health and Safety (OHS) management application for PT Hasnur Riung Sinergi coal mining operations with an offline-first approach specifically designed for coal mining areas with limited internet connection.

Develop and maintain SINERGI mobile application (Android & iOS) using Flutter.

Implement offline-first approach with automatic synchronization to support operations in the coal mining area.

Successfully released the application on Play Store & App Store.

Responsible for performance optimization, and dynamic business process adjustments.

Conducting UAT and Annual Evaluation at the coal mine jobsite.

Flutter, Dart, Clean Architecture, BLoC, Offline-First, Deep Link, Android, iOS, REST API, Firebase Cloud Messaging (FCM), WebSocket

Occupational Safety and Health (OSH) is a vital pillar in high-risk coal mining operations. PT Hasnur Riung Sinergi, a coal mining contractor, implements an OSH culture through the Quality Safety Assessment Program (QSAP), but faces operational constraints in its reporting system. These challenges stem from paper-based media and Google Forms, which lack flexibility due to one-way communication, limited notifications, and heavy reliance on internet connectivity. Consequently, corrective action verification is hindered, Person in Charge (PIC) assignment is non-personalized, and data accuracy declines.

This project aims to develop the frontend of an OSH management mobile application named SINERGI using the Flutter framework and an Offline-First approach to provide reporting functionality in low-signal areas.

The development method comprises requirements analysis, design, interface creation, backend integration, feature implementation (offline-first, drafts, and notifications), UAT, publishing, maintenance, and annual evaluations.

The project structure uses Clean Architecture to ensure the application is highly maintainable, future-proof, and easily testable. Features are grouped into general, master, and report module folders, each containing data, domain, and presentation layers.

User Acceptance Testing (UAT) and product evaluation by users were conducted on November 17-19, 2024 at several coal mining sites of PT Hasnur Riung Sinergi, South Kalimantan, Indonesia.

The results show that all frontend development stages were successfully implemented according to technical criteria. The application facilitates OSH reporting workflows among reporters, PICs, Area Supervisors (PJA), and Administrators. Users can complete Hazard, Inspection, and Observation reports offline, automatically sync drafts when internet connectivity is restored, and receive follow-up notifications.

An annual evaluation by visiting the coal mining site of PT Hasnur Riung Sinergi, South Kalimantan, Indonesia was conducted on December 12-13, 2025. This was done by conducting in-depth interviews with employees and workers at the site, as well as completing the System Usability Scale (SUS) questionnaire afterwards. The results of this activity provided feedback for continuous interface, workflow, and functional enhancements during the maintenance phase.

In conclusion, Flutter and the Offline-First approach effectively deliver a flexible and adaptive frontend application supporting OSH management operations at PT Hasnur Riung Sinergi.