Suitability of CAD-based Disassembly Sequence Plans for Flexible Remanufacturing

When products reach the end-of-first-life (EoFL), often recovery of valuable components is ignored because of unprofitable disassembly processes. Extracting the wanted component is a highly manual try-and-error process of disassembling multiple components. The creation of dis- and reassembly plans (e.g. for workers or robots) based on CAD files is currently too labour extensive and individually dependent on the EoFL state. Several studies exist for the automatic generation of assembly plans by CAD files with collision-based approaches. However, whether these approaches are suitable for industrial remanufacturing planning has not been discovered. This research compares the suitability of an AND/OR graph (AOG) and a precedence graph (PG) approach on ten exemplary examples. The suitability is measured with graph-based and visual feasibility checks as well as performance measures. The AOG approach is more promising than the PG approach because it considers the flexible formation of subassemblies and thus, better flexibility for scheduling in mixed-model disassembly lines. The results contribute to automatically deriving disassembly and reassembly plans for lot size one and saving labour-extensive high-wage planning effort. Overall, the resulting quality of assembly plans is highly dependent on the CAD model quality. Only two of the ten models resulted in suitable assembly plans. A preliminary CAD quality control during the design phase is needed to improve the applicability of the examined approaches.