Implementation of Double Exponential Smoothing Brown and Holt For Forecast Total Population in Medan City for Years 2023-2025

. Forecasting is an activity carried out to estimate or predict an event in the future. Double Exponential Smoothing Brown and Holt Method is a smoothing method commonly used in forecasting with linear trend data patterns. In doing a forecast, the error rate of a method greatly affects the accuracy of the forecast. The smaller the error rate, the better the forecasting is said to be and vice versa, if the error rate is getting bigger, then the forecasting needs to be evaluated. The error rate of a forecast can be measured using Mean Absolute Error (MAE) and Mean Absolute Percentage Error (MAPE). In this study, population forecasting of Medan City was carried out using the Brown and Holt double exponential smoothing method with the aim of knowing the population of Medan City in 2023-2025. Forecasting is done based on population data from 2010-2022. Based on the calculations carried out with the Brown method (α = 0,5), the population forecast of Medan City in 2023 amounted to 2.548.677 people or an increase of 2.17% from 2022 and in 2024 and 2025 respectively increased by 4,15% and 6,13% with an MAE value of 23116.790 and MAPE of 0,9848%. Calculation using the Holt method (α=0,9 and γ=0,1) resulted in a forecast of the population of Medan City in 2023 of 2.524.962 people or an increase of 1,22% from 2022 and in 2024 and 2025 an increase of 2,45% and 3,69% respectively, and the MAE value of 19587 and MAPE of 0,8301%.