Demand forecasting is an important part of decision making for businesses, helping them plan for inventory and capacity. It involves predicting customer demand using both qualitative and quantitative methods, such as statistical modeling and market research. Forecasting can be done through a demand planning process or by using mathematical forecasting models based on historical data. There are also two main approaches to forecasting: qualitative and quantitative. Qualitative methods are commonly used in traditional forecasting and involve analyzing trends and customer preferences, while quantitative analysis uses mathematical models to make predictions. Both methods can help businesses make informed decisions and strategies in operations management.