In some situations it is necessary that each order that is created be of a fixed quantity.  When the Item setting "Order by batches", is set to "Yes", the requirement plan breaks the daily (or weekly) periodic order requirements into multiple smaller orders that are equal to the specified fixed batch size.

To access the "Order by batches" setting, click on a SKU to open up the Item Details, and navigate to the Options tab of the SKU.  From the Options tab, navigate to the Requirement Planning Settings, and look for the "Pack/batch size" and "Order by batches" fields.

The "Pack/batch size" field is used to specify the fixed size that should be used to create each suggested order. After the "Pack/batch size" field is set, toggle the value of the Order by batches" field to Yes to have the suggested orders for this SKU created with the specified fixed batch size.

After the Order by batches" field is set to "Yes", each order that is created by the requirement plan will be equal to the specified "Pack/batch size".  The example below shows how the setting breaks the requirement of 100 units due on March 13 into 4 orders of 25 each.

This use of the "Order by batches" setting is also reflected in the planner action with each batch being displayed as its own order line.