<![CDATA[The development of information technology has driven significant transformation in the retail trade sector, including the online fashion industry in Indonesia. The shift in consumer behavior towards online shopping requires businesses to adopt effective Customer Relationship Management (CRM) strategies to increase customer satisfaction, loyalty, and customer management efficiency. This study aims to design and implement a WhatsApp Business-based CRM application to optimize the sales system in fashion MSMEs, with a case study in the online fashion sector. The research method used is a descriptive qualitative approach, using interviews, observations, and literature reviews. The results show that manual use of WhatsApp Business creates obstacles, including delayed responses, unstructured customer records, and limited consumer behavior analysis. The developed CRM application integrates the WhatsApp Business API with a customer database and a web-based admin dashboard. Key features include contact management, transaction history recording, auto-reply, customer segmentation, and promotional broadcasts. Testing using the black-box method and user validation demonstrates that the system runs optimally, accelerates response times, improves communication efficiency, and provides real-time customer analysis.Perkembangan teknologi informasi telah mendorong transformasi signifikan pada sektor perdagangan ritel, termasuk industri fashion online di Indonesia. Pergeseran perilaku konsumen menuju belanja daring menuntut pelaku usaha untuk mengadopsi strategi Customer Relationship Management (CRM) yang efektif dalam meningkatkan kepuasan, loyalitas, serta efisiensi pengelolaan pelanggan. Penelitian ini bertujuan merancang dan mengimplementasikan aplikasi CRM berbasis WhatsApp Business guna mengoptimalkan sistem penjualan pada UMKM fashion, dengan studi kasus di Sektor fashion online. Metode penelitian yang digunakan adalah kualitatif deskriptif melalui wawancara, observasi, dan studi pustaka. Hasil penelitian menunjukkan bahwa penggunaan WhatsApp Business secara manual menimbulkan kendala berupa keterlambatan respons, pencatatan pelanggan yang tidak terstruktur, serta keterbatasan analisis perilaku konsumen. Aplikasi CRM yang dikembangkan mengintegrasikan WhatsApp Business API dengan basis data pelanggan dan dashboard admin berbasis web. Fitur utama mencakup manajemen kontak, pencatatan histori transaksi, auto-reply, segmentasi pelanggan, dan broadcast promosi. Pengujian menggunakan metode black-box dan validasi pengguna membuktikan bahwa sistem berjalan optimal, mempercepat respons, meningkatkan efisiensi komunikasi, serta menyediakan analisis pelanggan secara real-time.]]>
