Conclusion
Forecasting methods at the heart of decision making

Several forecasting methods have emerged over the decades to meet the growing need for decision-making in an uncertain environment. These decisions, which range from the strategic to the operational level, often have a significant impact on the cost of goods sold and customer service levels. As presented in this article, forecasting methods can be qualitative, relying on human judgment, or quantitative, relying on statistical tools. They can also be simple or highly sophisticated, inexpensive or very expensive, and so on.

The choice of a forecasting method depends on the forecasting horizon, the availability of historical data, and information on the external factors influencing the variable to be forecast. The longer the planning horizon, the less reliable the forecast. On the other hand, the more historical data and exogenous information are available, the more...