Every industrial organization, whether it deals with an assembly or a disassembly process, is definitely putting a huge focus on how to optimize its operative mode by reducing: process variation, frequent changes of production tools, quality issues, wastes. That’s why, disassembly plan generation (DP) is a very supportive tool that detects and identifies difficulties and probable blocking assembly/disassembly situations from the early design steps and avoid them. This anticipation is quite beneficial to manufactories point of view cost, time and quality of products as it returns with a remarkable reduction in production stopping time and products’ defects, as a result reduction in cost of production. In order to ameliorate DP algorithm decision generation and make it very similar to real manufacturing circumstances, this article comes with a new approach that combines between two main metrics, which are the Quality index (Qi) and the Timing index (Ti), as criteria while selecting optimal and feasible DP. Qi is calculated based on the failure mode, effects and criticality analysis method (FMECA), on the other side, Ti represents the real processing time index with reference to real manufacturing constraints (workplace, lay-out, work-flow, tools, machines…). To highlight the effectiveness of the proposed approach, an industrial gear box example is simulated and compared to a literature study.