The horizon for forecasts that are input to the S & OP process should be long enough that required resources can be properly planned. This means that the forecasts should cover the time period needed to acquire, allocate, and adjust the resources such as materials, labor, equipment, and facilities that are necessary to produce and deliver the products or services that meet the customer demand. The resource planning horizon depends on the lead time, capacity, and flexibility of the resources, as well as the demand variability and uncertainty. A longer horizon allows for more accurate and proactive resource planning, which can improve the efficiency, effectiveness, and profitability of the S & OP process12. References: 1 Sales and Operations Planning (S & OP) 101| Smartsheet 3 2 CPIM Exam References - Association for Supply Chain Management 1