This document discusses forecasting in manufacturing and mechanical engineering. It defines forecasting as an estimate of uncertain future events used to improve decision-making and planning. Several types of forecasts are described, including short, intermediate, and long term forecasts used for inventory control, production planning, and facility planning. Common forecasting methods like informed opinion, Delphi method, market research, and historical analogy are outlined. The document also covers forecasting techniques like simple and weighted moving averages, exponential smoothing, and seasonal adjustments. It defines forecast error and common metrics to evaluate forecast accuracy like MAD, MAPE, and MSE. In conclusion, the author acknowledges sources for the forecasting information and expresses gratitude to faculties, parents, and friends.