Fixed Lot Size 
Fixed Lot Size
Use
It is useful to select a fixed lot size for a material, if it is only delivered, for example, in pallets of a certain quantity or in tanks of a certain size.
Prerequisites
You have set the indicator FX and entered the fixed lot-size quantity in the Lot size field in the material master (MRP 1 view) for the material.
Features
When planning using fixed lot size, the system will use the fixed order quantity recorded in the material master for the lot-size calculation if a material shortage exists. If the fixed lot size is not sufficient to balance out the material shortage, then several lots are planned for the same date until the material shortage is eliminated.
You can specify a threshold value for the maximum number of order proposals for the fixed lot size in Customizing for MRP in the IMG activity Define error processing in the planning run. If this value is exceeded, that is, if too many procurement proposals are created for a date and for a material, the material is provided with a termination message.