Parallel disassembly sequence planning for complex products based on fuzzy-rough sets

The goal of the parallel disassembly sequence planning (PDSP) is to find an optimal feasible disassembly task sequence with many constraints. Due to the PDSP of complex product is restricted by various factors, the DPSP problem is not easily solved in a general form. In order to reduce the time complexity, this paper presents a PDSP method based on fuzzy-rough sets. Five disassembly factors including assembly constraints factor, disassembly precedence factor, disassembly time factor, disassembly tool factor, and combination type factor are defined and formulated. In light of the characteristics of PDSP, the fuzzy-rough set mapping model of parallel disassembly is constructed. The components to be disassembled are taken as knowledge universe, and disassembly membership function as objection function is defined as the indiscernibility relation. Then, the fuzzy-rough set mapping model of parallel disassembly is adopted to generate the optimum parallel disassembly sequence. Finally, two examples validate the proposed method.