Forecast methods in supply chain are the official business definitions used to predict the future demand for goods and services. These methods help businesses to make informed decisions on inventory levels, pricing, and production. They are used to plan for future demand and ensure that the supply chain is able to meet the needs of customers. The most common forecast methods used in supply chain are time series analysis, regression analysis, and causal analysis. Time series analysis uses historical data to predict future demand, while regression analysis looks at the relationship between variables to make predictions. Causal analysis looks at the underlying causes of demand and how they might affect future demand. All of these methods help businesses to make informed decisions about their supply chain and ensure that they are able to meet customer demand.