A system and method is disclosed for computing optimal inventory targets in bill of materials in a multi-echelon supply chain. The system includes one or more memory units and on or more processing units collectively configured to determine a delay time from at least one second plan level node in an at least second indenture plan level to at least one first plan level node in a first indenture plan level. The one or more memory units and on or more processing units is further collectively configured to determine a delay time from the at least one first plan level node in the first indenture plan level to a finished good.