Nowadays, global sustainability is the central issue in recycling and, increasingly, in manufacturing. Recycling used products can save energy, natural resources, and landfill space, and can reduce air pollution. It can give used products new lives. The study of disassembly is needed in order to make recycling economical, and disassembly sequence generation (DSG) plays an important role. An appropriate disassembly process plan can minimize the cost spent on the disassembly processes and maximize the benefits coming from the reused components. In the current paper, a new approach using Petri net modelling to generate an optimal disassembly sequence (ODS), based on accessibility and end-of-life (EOL) strategy, is described. The different life spans of the reusable components affect the disassembly order, especially in destructive disassembly, and the influence of components with different life spans on DSG is analysed. First, AND/OR graphs are used to generate all feasible disassembly sequences, and then AND/OR graphs are transferred into Petri net graphs while accessibility values and life span values of components are taken into account to obtain the ODS. A program using Microsoft Cþþ is developed to generate the ODS. The disassembly of a C-clamp is used as a trial example.