Consumption Strategies and Logic 
Purpose
In the consumption process, the system compares planned independent requirement quantities and dates with actual customer requirements.
The consumption process is defined for every planning strategy in Customizing for Demand Management by the combination of a requirements type from Demand Management with a requirements type from sales order management.
This means that the requirements type entered when maintaining planned independent requirements is compared with the customer requirements type specified in Customizing.
Prerequisites
- You must maintain the consumption mode in the material master record (MRP screen) or in Customizing for Demand Management. The consumption mode determines whether consumption is to be carried out as backward or forward consumption, or whether both consumption types are allowed.
- In backward consumption, the system looks for the planned independent requirement quantity that lies directly before the sales order.
- In forward consumption, the system looks for the planned independent requirement quantity that lies directly after the sales order.
- You must maintain the consumption period in the material master record (MRP screen) or in Customizing for Demand Management. The consumption period (either forward or backward) is specified in workdays and is valid from the current date. Sales orders, material reservations, dependent requirements then consume the planned independent requirement quantities that lie within the consumption period and after (for forward consumption) or before (for backward consumption) the requirements date.
Process Flow

- The customer requirement consumes the planned independent requirement quantity that lies either directly before it or directly after it.
- If the planned independent requirement quantity that lies directly before the customer requirements does not cover the customer’s requirement, then the system looks for the next closest planned independent requirements either in the future or the past.
- During this process, the system refers to the consumption periods maintained in the material master or in Customizing for Demand Management (see above). The consumption periods determine the intervals (for backward or forward consumption) within which customer requirements consume planned independent requirements. Customer requirements which lie outside the consumption period are not consumed.

If no consumption periods have been maintained, you can only consume requirements which are planned on the same day.
The allocation of customer requirements to planned independent requirements is carried out dynamically. This means that if sales orders or planning is rescheduled, the allocation is deleted and redefined.