Greedy algorithm for disassembly line scheduling

2005

SPIE Proceedings

Disassembly takes place in remanufacturing, recycling and disposal, with a line being the best choice for automation. The disassembly line balancing problem seeks a sequence which: is feasible, minimizes workstations, and ensures similar idle times, as well as other end-of-life specific concerns. Finding the optimal balance is computationally intensive due to exponential growth. Combinatorial optimization methods hold promise for providing solutions to the disassembly line balancing problem, which is proven here to belong to the class of unary NP-complete problems. Probabilistic (ant colony optimization) and uninformed (H-K) search methods are presented and compared. Numerical results are obtained using a recent case study to illustrate the search implementations and compare their performance. Conclusions drawn include the consistent generation of near-optimal solutions, the ability to preserve precedence, the speed of the techniques, and their practicality due to ease of implementation.

Section: Literature Reviewmentioning

confidence: 99%

<title>Uninformed and probabilistic distributed agent combinatorial searches for the unary NP-complete disassembly line balancing problem</title>

McGovern

2005

SPIE Proceedings

“…Gungor and Gupta [7] provide a comprehensive survey of issues in environmentally conscious manufacturing and product recovery. Within the area of disassembly, disassembly line has become the subject of recent interest [5], [6], [19], [22]. Korugan and Gupta [16] suggest an adaptive way of implementing kanbans to a single-stage hybrid system.…”

Section: Literature Reviewmentioning

confidence: 99%

<title>Multi-kanban mechanism for personal computer disassembly</title>

Udomsawat

Environmentally Conscious Manufacturing IV

Kamarthi

2004

The use of personal computers (PCs) continues to increase every year. According to a 1999 figure, 50 percent of all US households owned PCs, a figure that continues to rise every year. With continuous development of sophisticated software, PCs are becoming increasingly powerful. In addition, the price of a PC continues to steadily decline. Furthermore, the typical life of a PC in the workplace is approximately two to three years while in the home it is three to five years. As these PCs become obsolete, they are replaced and the old PCs are disposed of. It is estimated that between 14 and 20 million PCs are retired annually in the US. While 20 to 30% of the units may be resold, the others are discarded. These discards represent a significant potential source of lead for the waste stream. In some communities, waste cathode ray tubes (CRTs) represent the second largest source of lead in the waste stream after vehicular lead acid batteries. PCs are, therefore, not suitable for dumping in landfills. Besides, several components of a PC can be reused and then there are other valuable materials that can also be harvested. And with the advent of product stewardship, product recovery is the best solution for manufacturers. Disassembly line is perhaps the most suitable set up for disassembling PCs. However, planning and scheduling of disassembly on a disassembly line is complicated. In this paper, we discuss some of the complications including product arrival, demand arrival, inventory fluctuation and production control mechanisms. We then show how to overcome them by implementing a multi-kanban mechanism in the PC disassembly line setting. The multi-kanban mechanism relies on dynamic routing of kanbans according to the state of the system. We investigate the multi-kanban mechanism using simulation and demonstrate that this mechanism is superior to the traditional push system in terms of controlling the system's inventory while maintaining a decent customer service level

“…Gungor and Gupta [4] provide a comprehensive survey of issues in environmentally conscious manufacturing and product recovery. Other studies on disassembly and product recovery have been presented by Brennan et al [1], Gupta and McLean [9], Lambert [13] and McGovern and Gupta [15]. A recent book by Lambert and Gupta [14] is also helpful in understanding the areas of disassembly and disassembly modeling.…”

Section: Introductionmentioning

confidence: 97%

<title>The effect of sudden server breakdown on the performance of a disassembly line</title>

Udomsawat

2005

SPIE Proceedings

Product and material recovery relies on the disassembly process to separate target components or materials from the endof-life (EOL) products. Disassembly line is especially effective when products in large quantity are disassembled. Unlike an assembly line, a disassembly line is more complex and is subjected to numerous uncertainties including stochastic and multi-level arrivals of component demands, stochastic arrival times for EOL products, and process interruption due to equipment failure. These factors seriously impair the control mechanism in the disassembly line. A common production control mechanism is the traditional push system (TPS). TPS responds to the aforementioned complications by carrying substantial amounts of inventories. An alternative control mechanism is a newly developed multi-kanban pull system (MKS) that relies on dynamic routing of kanbans, which tends to minimize the system's inventories while maintaining demand serviceability. In this paper we explore the impact of sudden breakdown of server on the performance of a disassembly line. We compare the overall performances of the TPS and MKS by considering two scenarios. We present the solution procedure and results for these cases.