FORECASTING GAMIS DEMAND IN FASHION GALLERY USING WEIGHTED MOVING AVERAGE

: This research will discuss predictions of demand for robes at the Fashion Gallery. The problem that occurs is that there is often a buildup in the number of robes provided in shops, thereby increasing additional expenses, such as storage costs and demand costs. On the other hand, if there is too little stock of robes, it will result in losses because potential buyers do not get the items they need. In this case, the forecasting system will be used as a tool to solve the problem of robe accumulation. The WMA method prioritizes the most recent data points while smoothing out fluctuations. The advantage of this method is increased responsiveness to recent changes in demand patterns, contributing to more accurate forecasts by considering current information more prominently than historical data. By implementing the WMA method, it is hoped that the accumulation of robes can be avoided. From the results of prediction calculations in January 2024, it is predicted that there will be 143 adult robes, with a MAD of 7.685185, MSE 74.79938 and MAPE 5%. For small children's robes, it is predicted that there will be 56 shirts, with MAD of 8.388889, MSE of 91.16358 and MAPE of 12%. It can be concluded that the WMA method can make it easier for Fashion Gallery to predict demand for adult and children's robes in the following month.


INTRODUCTION
Fashion business has now become an inseparable part of people's lives, especially because clothing is an essential need that cannot be avoided in various daily activities [1].Looking stylish and following the latest trends is a way to look cooler and in line with the times [2].
One type of clothing that is popular, especially when celebrating Eid, is the robes, especially for women [3].In this scenario, robe clothing items are predominantly retailed through boutique establishments [4].
Fashion Gallery is a business operating in the fashion sector that has been established since 2020.The products marketed by Fashion Gallery include tops, robes, trousers and skirts.
The analysis revealed issues within the Fashion Gallery relating to an accumulation of robe, attributed to mismatches between demand and supply dynamics.An interview with the proprietor, Tiyan Anggreani, elucidated that discrepancies exist between the volume of robe requests and available supplies.For example, in November 2023, the demand for robe was reported at 40 units, yet the supply stood at 65 units, leading to an excess inventory situation.Consequently, this mismatch resulted in a surplus of robs by December 2023.
In response to the identified issue, a proposed solution entails implementing a forecasting system capable of predicting forthcoming demand volumes.Such a system aims to optimize inventory management, mitigate the accumulation of excess robes, and enhance profitability within the fashion gallery.By accurately forecasting demand trends, the proposed system seeks to streamline supply chain operations, thereby minimizing the financial burden associated with surplus inventory and maximizing revenue potential.
Predictions of future trends or events based on past data or forecasting will be used to predict total demand that will come in the following month [5].The forecasting method that will be used is the Weighting Moving Average method [6].
Weighted Moving Average (WMA), method involves assigning varying weights to recent data points compared to older ones [7].This approach emphasizes recent trends while smoothing out fluctuations, aiding in more accurate forecasting by prioritizing current information over past data [8].
In the study titled "Prediction of 35,000 All Clothes Sales Range Using WMA Method", it was determined that employing the Weighted Moving Average (WMA) method enabled successful anticipation of clothing sales figures for the subsequent month [9].
In the research endeavor titled "Implementation of E-Forecasting on Jimmy Fish Using the Weighted Moving Average Method", it was deduced that the adoption of a forecasting system facilitated the accurate prediction of fish stock quantities based on preceding month's data [10].
In the study titled "A System for Predicting the Amount of Clothing Production Using a Weighted Moving Average", it was determined that the employment of the Weighted Moving Average (WMA) method enabled the accurate anticipation of clothing production quantities for the ensuing month, thereby mitigating instances of duplication [11].
This research presents notable advantages in its utilization of the PHP 7programming language, complemented by a framework.Furthermore, the developed system exhibits versatility by extending its predictive capabilities beyond monthly forecasts to include predictions for subsequent days or weeks, enhancing its applicability and utility within the domain of forecasting.
The implementation of this system within the fashion gallery is poised to facilitate predictive forecasting of robe demand for the subsequent month [12].

METHOD
Research methodology refers to the systematic steps used in a study to collect, analyze, and interpret data.Research methodology helps to design and conduct research in a reliable and valid manner.

Studying Literature
Search for reference information in the form of books, journals and study materials related.

Data Collection
Data was collected through observations and interviews with Tiyan Anggreani, the proprietor of the Fashion Gallery, followed by processing of the acquired data.The data that will be used in this research is historical data requests for gamis clothes, from January 2023 to December 2023.

System Planning
The architectural design stage involves the conceptualization and specification of the system architecture.This key step in software development is designing the basic structure of the system to be built, determining how the components will interact with each other, and establishing a framework that will be the basis for further development.This stage creates a holistic view of how the system will operate and interact with its environment.

System Implementation
Next stage, the software development cycle where the design that has been created is realized into code that can be run.The stages in the research method carried out in Image 1.

Algorithm Weighted Moving Average
The system that will be created is a forecasting system for predicting demand for robes using the Weighted Mov-ing Average method.calculations using the Weighted Moving Average (WMA) method are as follows [5]: (1) Description: X t : Actual data in a certain period (t).W : Weight Forecasting error measured by comparing actual data for the the period with forecast results for the same period.If the resulting error rate is smaller, the forecasting results will be more accurate.

𝐸𝑡 = 𝑋𝑡 − 𝑓𝑡
(2) Description: Et : Error value X t : Actual data for the t-th time period F t : Forecast for the t period

RESULT AND DISCUSSION
The data that will be used in this research is historical data on the number of requests for robes clothes, from January 2023 to December 2023.In implementing the calculation procedure utilizing the Weighted Moving Average (WMA) method, it is essential to ascertain the weights designated for use in the computation.Subsequently, in table 2, the outcomes of forecasting computations for adult robes will be delineated.
Furthermore, in table 3, the findings of forecasting computations for robes intended for children be presented.
the assessed errors (direct value of each error) can use the following equation: Squared error value n : Lots of data

Table 1 .
Data on Demand Robes

Table 2 .
Analysis of Prediction Errors in Demand for Adult Robes

Table 3 .
Calculation of Predictions for Demand for Children's Robes