A computer implemented method, apparatus, and computer program product for managing an ancestry tree. An order to build a product is received. The ancestry tree is created. The ancestry tree comprises a set of nodes, where each node represents a part of the product. A request to determine a higher level sub-assembly containing a specific part is received. The node of the specific part is located in the ancestry tree. An ancestor pointer in the node of the specific part is returned. The ancestor pointer indicates a higher level sub-assembly containing the part.