Pusattinta.com Store is engaged in selling printer ink. The problem faced is difficult to determine the amount of stock to meet customer needs and not cause accumulation of goods for a long time. With the above problems, a forecasting application was made using the Java programming language with the WMA, SMA, and DES methods. The WMA method is assigned a different weight for each available past historical data, SMA is a value smoothing forecasting method by taking a group of observed values ??and looking for the average, DES processes smoothing twice. Where each data is given a weight symbol. The magnitude of is 0 to 1. From the 3 methods, it is known that the average MSE of each method is WMA : 102,898.57, SMA : 89,579,446 and DES : 87,156,989. The method with the smallest MSE average is the most appropriate method to use.
