An assembly model is identified including a plurality of part models. Each part model is a predefined, selectable model corresponding to at least one part in a plurality of assembly parts. The assembly model is presented and a sequence of user selections identifying part models in the assembly model are received through a user interface. User selections can correspond to designations of parts to be removed from the modeled assembly during a disassembly of the assembly. Selected part models are removed from the displayed presentation in response to corresponding user selections. A disassembly order is generated including an ordered grouping of disassembly steps, each disassembly step corresponding to a user selection of a part model in the sequence of user selections. The disassembly steps are ordered based on an order of selection of the corresponding part models. The order of the disassembly order is reversed and an assembly order is generated for the assembly from the reversed disassembly order.