Software for integration of end-of-life option determination, disassemblability evaluation and disassembly sequencing optimization

Abstract

In recent years, many countries have developed new legislations which are aimed at greater emphasis to force vehicle manufacturers to recycle their products at the end of their life. However, before end-of-life vehicles can be recycled, end-of-life disassembly needs to be put in place. It entails large amounts of capital expenditure and time. Besides that, in general, vehicle designers also do not have experience in disassembling and recycling to determine impact of various design aspects on difficulty at the disassembly stage. Therefore, there is a strong need for a tool to determine end-of-life options, to evaluate the disassemblability, and to search for the optimal end-of-life disassembly sequence of the end-of-life vehicles. This research was conducted to fulfill those needs. The main outcome of this research is the methodology developed to aid vehicle designers to analyze the disassemblability and recyclability of end-of-life vehicles. The developed methodology integrated three important aspects in one framework. Those aspects are: (1) end-of-life option determination; (2) disassemblability and recyclability analyses; and (3) disassembly sequence determination. The condition and material composition of the end-of-life vehicle components are the criteria for determining the end-of-life option. The numerical evaluation of disassemblability and the recyclability computation method used in the end-of-life vehicle recycling manual are applied to evaluate the disassemblability and recyclability. In order to optimize the disassembly sequence, Mix Integer Linear Programming (MILP) technique is used. The end-of-life option determination will guide the designer to choose the appropriate end-of-life option of the product. The disassemblability evaluation will aid the designers in reducing the difficulty for disassembly, disassembly time and disassembly cost required. The recyclability analysis will show that the design meets or does not meet the legislation at feasible expenditure in terms of recycling target. The searching for optimum disassembly sequence will minimize the disassembly cost and maximize the end-of-life value and finally increase the profitability. Based on the developed methodology, computer software was developed to ease the tasks of decision making. The Visual Basic programming language, Microsoft Access and LINDO systems were applied in the proposed software. The proposed software was developed specially to assist vehicle designers to evaluate vehicle design with respect to the legislation, recycling and economic value. In order to verify and validate the developed software, an end-of-life car door was introduced with the intention to investigate the appropriate end-of-life option for its components, disassemblability, suitability for recycling, recyclability and the optimum disassembly sequence. The result of the case study showed that the developed software can estimate the disassembly time of the car door without any significant differences with the actual disassembly operation.