A mathematical formulation for processing time computing in disassembly lines and its optimization

Disassembly is the first practice in maintenance and recycling of industrial products. For productivity and efficiency, it is necessary to optimize its operative manners by reducing: change of tools and directions, process variation, wastes, etc. The simulation of Disassembly Plan (DP) allows the detection and identification of difficulties from the design stage in order to avoid them. This paper proposes a mathematical formulation which combines two principal indicators: the index of Quality (Qi) and the index of processing Time (Ti) in order to choose the best and feasible disassembly plan. The Failure Mode, Effects and Criticality Analysis method is implemented to compute Qi. Ti is obtained according to real manufacturing constraints (workspace, layout, tools, machines, etc.). Based on 5S method, the workspace can be optimized which directly impacts the timing index and contribute to the selection of the best DP. A gear box is used to show up the efficiency of the proposed approach.