Disassembly sequence planning for complete disassembly in product recovery

ABSTRACT Disassembly is a key element for retrieving the desiredsubassemblies and/or parts from a product. However,determining an efficient disassembly sequence plan (DSP)is an NP -complete problem. In this paper, we propose amethodology to generate a near optimum DSP for aproduct. The methodology is illustrated using an example. INTRODUCTION Product recovery and waste management techniques are inpopular demand as key elements of EnvironmentallyConscious Manufacturing as a result of fast depletion ofvirgin resources and increasing amount of waste [2], [4].Product recovery generally offers two major options:recycling and remanufacturing. Recycling aims to recoverthe material content of retired products by performing thenecessary disassembly, sorting, and chemical operations.Remanufacturing preserves the product’s (or its part’s)identity and performs the required disassembly, sorting,and refurbishing operations in order to bring the parts ofthe product to a desired level of quality.Products arrive at a recycling or remanufacturing facilitywhen they finish their useful lives (that is, when theproduct is no longer the customer’s choice either because itdoes not function properly, or its lease has expired or it isout of fashion or outdated etc.) Disassembly is considereda key element for retrieving the desired parts and/orsubassemblies from the products. Examples of disassemblyobjectives include:• Recovery of valuable parts or subassemblies (in shortsupply) which are common to other products still beingproduced,• Retrieval of parts or subassemblies of discontinuedproducts to satisfy a sudden demand for these parts,• Removal of hazardous parts,• Increasing the purity of the remainder of the product,• Extraction of the parts from the remainder of theproduct which will be sent to inventory for future use,• Decreasing the amount of shredder residue and theamount to be sent to landfills, and• Achieving environmentally friendly manufacturingstandards (i.e. meeting the ratio of the use of recycledmaterials in production to new products).The purpose of this paper is to present a methodology toobtain a near optimal DSP which satisfies a given set ofconstraints defined by the product being disassembled aswell as by the disassembly system.