A hybrid method for forecasting with an introduction of a day of the week index to the daily shipping data of sanitary materials

摘要

Correct sales forecasting is inevitable in industries. In industries, how to improve forecasting accuracy such as sales, shipping is an important issue. There are many researches made on this. In this paper, we make estimation of ARMA model parameter and then estimate smoothing constants. Combining the trend removing method with this method, we aim to improve forecasting accuracy. Furthermore, "a day of the week index" is newly introduced for the daily data and the forecasting is executed to the manufacturer's data of sanitary materials. We have obtained good result. The effectiveness of this method should be examined in various cases.