What is forecasting in production planning?

In production planning, we are primarly interested in in forecasting product demand. Because demand is likely to be random in most circumtances, can forecasting methods provide any value? Mostly yes. Although some portions of the demand process may be unpredictable, other portions may be predictable. Trends, cycles and seasonal variation may be present, all of which give us an advantage over trying to predict the outcome of a coin toss.