Planning Step Links 
Planning Step Links
Use
Use planning step links to exchange planning data between linked planning steps. This moves planning steps from the source planning step to the target planning step. Planning steps can be both targets and sources. You can create as many links as you require for each combination of source and target planning steps. Use the link numbers to differentiate between source and target planning steps.
Features
Select one link method only to define a planning step link in Customizing: Use the link method to define links between planning steps. Use the following methods:
You only want to define documentation that describes a planning step link.
You want to copy planning step data to its linked planning step using SAP Copy Management. You also want to process the data at the same time. The copy method in SAP Copy Management defines the method used to process data. For example, data is aggregated while it is being copied. To do this, a database table must be assigned to both planning steps in planning step maintenance.
For more information on SAP Copy Management in Customizing for Merchandise and Assortment Planning, see Tools.
You can choose to state a link program or a transaction for the link. This enables you to integrate your own developments in the planning process when you exchange planning data.