Delete Dependent Orders Heuristic 
You can use this heuristic, SAP_PP_024, to delete all pegged dependent orders across BOM levels. This includes all sub-assemblies and purchase requisitions that are pegged to the selected order. The heuristic can be executed only at the order level.
The heuristic reads the order network for the selected order across the BOM levels. It marks for deletion all dependent orders that are neither fixed nor firmed nor pegged to any other order not yet marked for deletion. When it reaches the end of the order network, the heuristic deletes the marked dependent orders.
If you select a demand element (forecast or dependent demand), then all planned orders or purchase requisitions pegged to the requirement and subsequent orders in the pegging network are deleted. If you select a receipt element (planned order or purchase requisition), then all orders pegged to the dependent demand or stock transfer reservation are deleted.
The dependent orders you wish to delete are neither of the following:
Firmed
Pegged to another demand that is outside the scope of selection
Subject to fixed pegging
The heuristic reads the order network in the downward direction and marks for deletion all dependent orders satisfying the prerequisite criteria. When it reaches the end of the order network, the heuristic deletes the marked dependent orders.
You can also execute this heuristic from the Product View, Product Planning Table, the Detailed Scheduling Planning Board, and the Production Planning Run.