Offline-first warehouse management for remote mining: A Progressive Web Application deployment in East Kalimantan

Warehouse operations at remote coal mining sites often rely on paper-based processes because cloud-dependent systems fail under intermittent connectivity. This paper reports on the design, deployment, and twelve-week field evaluation of a Progressive Web Application (PWA) built with Next.js for warehouse management at a coal mine in Berau, East Kalimantan, Indonesia. The site experiences average daily network outages of 6.4 hours, ruling out conventional cloud-based warehouse management systems. The application implements an offline-first architecture using service workers and IndexedDB, with a hybrid synchronization engine that applies commutative conflict resolution for inventory quantity changes. Over twelve weeks of production use across 8,247 transactions (47.2% performed offline), the system achieved a 69.1% reduction in transaction processing time, a 67.4% reduction in data entry errors, and a synchronization success rate of 99.5%. A System Usability Scale assessment with 12 warehouse operators yielded a score of 78.5. While results are drawn from a single-site deployment, the paper contributes a replicable architectural pattern and empirical evidence for PWA deployment in connectivity-constrained industrial settings.