Pengembangan Sistem Informasi Prediksi Penjualan Kue Menggunakan Metode Weighted Moving Average pada Toko Kue Nyonya Yati, Jakarta Selatan

Abstract

This study aimed to develop a web-based sales prediction information system using the Weighted Moving Average (WMA) method at Nyonya Yati Cake Shop, South Jakarta. The shop recorded and managed sales data manually, which made it difficult to retrieve historical sales information and left it without a calculation-based means of estimating sales for the next period. The study used a descriptive qualitative approach, with data collected through observation, interviews, and a literature review. The system was developed following the Waterfall model, which comprises requirements analysis, design, implementation, testing, and maintenance, and was built as a website using PHP, MySQL, XAMPP, HTML, CSS, and JavaScript. It provides product, stock, sales, user account, reporting, and forecasting features. The WMA method assigns different weights to historical observations, with more recent sales data given greater influence. In the calculation example for Cheesecake, sales data from January to December were used with a forecasting configuration of MA=3. The forecasts were 541 pcs for April, 542 pcs for May, and 541 pcs for June, and the forecast for January of the following period (t = 13) was 540 pcs. Forecast errors were evaluated using the tracking signal, which had a final value of −3.000. The system organizes sales data in a structured way, and its forecasts can serve as a consideration for stock, production, and sales planning.