In an advanced planning system (APS), the demand planning module feeds the master planning module. Demand planning involves forecasting customer demand and creating a demand plan that considers historical data, market trends, and other factors. This information is crucial for the master planning module, which uses it to develop production, procurement, and inventory plans to meet the forecasted demand efficiently.

Purchasing planning focuses on procurement activities and is influenced by the master plan.

Distribution planning deals with the logistics of distributing products and relies on the master plan.

Fulfillment planning involves ensuring customer orders are fulfilled, also based on the master plan.