Long-term planning allows you to simulate materials planning, in parallel to operational materials planning, across all low-level codes. This means that you can use the current bills of material to determine the effects of a planned production program on the material requirements and the capacity load.

In the standard R/3 System, long-term planning affects all low-level codes.
However, if the BOM is very large, long-term planning can affect system performance. For this reason, you can switch off long-term planning for a low-level code if it is no longer required.