“…In recent years, several methods have been proposed to model and forecast product demand, such as Bayesian Model (Lee, Lee & Lee, 2012;Pezzulli et al, 2006), Neural Network (Tilokavichai & Sophatsathit, 2011;Lau, Ho & Zhao, 2013;Singhal & Swarup, 2011;Yu & Huarng, 2010), Times Series Analysis (Box, Jenkins & Reinsel, 2013;Hunt & Amarawickrama, 2008;Zhang, Huang & Zhao, 2013), Grey Theory (Yao, Chi & Chen, 2003;Hsu & Chen, 2003) Genetic Algorithm (Haldenbilen & Ceylan, 2005) and so on. Exponential Smoothing Method (ESM) is often considered to apply for building forecasting model, which is developed by Robert G. Brown (Brown & Meyer, 1961).…”