Toko Alin Helm menghadapi keterbatasan dalam pengelolaan operasional yang masih dilakukan secara konvensional, mencakup pencatatan stok, pemrosesan pesanan, dan pemasaran produk yang bergantung pada interaksi tatap muka sehingga jangkauan pelanggan sangat terbatas. Penelitian ini bertujuan untuk merancang dan membangun sistem e-commerce berbasis web dengan model Business-to-Consumer (B2C) pada Toko Alin Helm menggunakan PHP dan MySQL. Metode pengembangan sistem yang digunakan adalah Waterfall dengan tahapan analisis kebutuhan, perancangan, implementasi, dan pengujian. Pengujian sistem dilakukan menggunakan Black Box Testing dan White Box Testing. Hasil penelitian menunjukkan bahwa sistem berhasil dibangun dengan mengintegrasikan tiga layanan utama dalam satu platform, yaitu penjualan produk helm dan aksesoris, jasa service helm, dan jasa cuci helm, dilengkapi fitur unggulan Helmet Size Guide, Campaign Management dan integrasi payment gateway. Hasil Black Box Testing terhadap 14 fungsi utama seluruhnya dinyatakan valid, sementara White Box Testing menghasilkan nilai Cyclomatic Complexity sebesar 7 dengan seluruh jalur logika telah terverifikasi. Sistem ini mampu menyelesaikan permasalahan operasional toko dan memperluas jangkauan pemasaran secara digital.

Alin Helm Store faced operational limitations due to conventional management practices, including manual stock recording, order processing, and product marketing that relied on face-to-face interactions, resulting in a highly restricted customer reach. This study aims to design and develop a web-based e-commerce system using the Business-to-Consumer (B2C) model for Alin Helm Store, built with PHP and MySQL. The system is developed using the Waterfall method, consisting of requirements analysis, design, implementation, and testing phases. System testing is conducted using Black Box Testing and White Box Testing. The results show that the system was successfully developed by integrating three main services into a single platform, namely helmet and accessories sales, helmet service, and helmet washing service, complemented by key features including a Helmet Size Guide, Campaign Management, and payment gateway integration. Black Box Testing on 14 core functions yielded entirely valid results, while White Box Testing produced a Cyclomatic Complexity value of 7 with all logical paths successfully verified. The system effectively resolves the store's operational challenges and expands its marketing reach through a fully digital platform.