Analysts use two methodologies to predict the demand for a product, namely the qualitative methodology and the quantitative methodology. In the quantitative approach, analysts use past product sales data to make future sales projections. They also take into account other factors, such as the sales period and seasonality in product demand. The qualitative approach is used when the amount of data and information in previous periods is not sufficient. This is a way to use intuitive criteria from the manager and his team. For example, the product sales team is able to provide insight into sales projection through their product experience.