Feasible Disassembly Sequences Research Articles

Research of Fuzzy Cost Model for Selective Disassembly Planning

In order to protect environment, the end-of-life product should be disassembly and recycled. While selective disassembly method can be used to separate the valuable parts from the old product and used for reuse or remanufacturing. Usually there are several feasible disassembly sequences for operation; the optimal sequence is decided by operation cost. A fuzzy cost model is presented instead of the traditional quantitative cost model. The advantage of this method is that the detailed information of the end-of-life product is not needed and, the practical feasibility of selective disassembly is improved.

A PROMETHEE Method Based Heuristic for Disassembly Line Balancing Problem

Disassembly of discarded products takes place in the process of remanufacturing, recycling, and disposal. The disassembly lines have been taken as available choice for automated disassembly; therefore, it has become essential that it be designed and balanced to work efficiently. The multi-objective disassembly line balancing problem seeks to find a disassembly sequence which provides a feasible disassembly sequence, minimizes the number of workstations and idle time, and balances the line for the disassembly of post consumed product by considering the environment effects. This paper proposes a multi-criteria decision making technique based heuristic for assigning the disassembly tasks to the workstations. In the proposed heuristic, the PROMETHEE method is used for prioritizing the tasks to be assigned. The tasks are assigned to the disassembly workstations according to their priority rank and precedence relations. The proposed heuristic is illustrated with an example, and the results show that substantial improvement in the performance is achieved compared with other heuristics.

Disassembly Sequence Planning of Steam Turbines for Virtual Maintenance

Disassembly Sequence planning is the important module of virtual maintenance. Its foundational task is to test the disassemblability of parts, find out all the feasible disassembly sequences of targeted parts and search for the near-optimal disassembly sequence. In the paper, the spherical algorithm is used to test the disassemblability of parts. And then the disassembly direction of parts is determined by rules which are the simplified version of Gaussian map approach. Thus the near-optimal disassembly sequence is found out by optimizing all feasible disassembly sequences of targeted parts by ant colony algorithm. The simulation result of the sequence optimization proves to be the same with manual calculation considering comprehensive cost of the change of disassembly tools and disassembly directions. The set of approaches can be reference for disassembly sequence planning of large-scale mechanical products.

Disassembly Sequence Planning Based on Poisoning Ant Colony Algorithm

Disassembly of scrap product is a necessary procedure of products recycling and reusing, which is an important part of whole life cycle of the products. Scrap product disassembly process planning can reduce the cost of disassembly operation. It can also improve operation efficiency and the enterprise competitiveness. A new improved algorithm is developed based on the basic ant colony algorithm, which is poisoning ant colony algorithm. Poisoning ant colony algorithm is applied to realize the search and optimization for feasible disassembly sequence solution set with disassembly root diagram. Finally, the optimal sequence is obtained based on evaluation objective function. Toxic environment and life value are also introduced to this algorithm. The characteristics of the algorithm are preferable search and convergence property.

Hierarchical Pipe System Disassembly Sequence Planning by Dynamic Self-Adaptive Tree Based Motion Planning

This paper represents a hierarchical pipe system disassembly method by using dynamic self-adaptive tree (DSAT) based motion planning to perform disassembly for a complex pipe system. A pipe system CAD model is prepared initially to indicate the environment of the disassembly procedure. The improved motion planning method provides basic algorithm support for indicating the feasible escape path of a single part. Our technic gradually reduces the complexity of the pipe system to generate a hierarchical structure which takes all geometric information of the system. The hierarchical structure is preserved and used for the generation of a disassembly relationship graph which indicates the feasible disassembly sequences.

Disassembly Matrix for Liquid Crystal Displays Televisions

Waste Electrical and Electronic Equipment (WEEE) are one of the most significant waste products in modern societies. Disassembly is a critical step to reduce Electrical and Electronic Equipment (EEE) waste. In the past two decades, despite disassembly has been applied to support recycling and remanufacturing of WEEE products worldwide, full disassembly of WEEE is rarely an ideal solution due to high disassembly cost. Disassembly planning and sequencing has therefore become an important but still a challenging research topic in recent years. In this paper, based on product model, space interference matrix can be generated to represent the space interference relationship between each component of product, and all feasible disassembly sequences can be obtained by analysing the space interference matrix in six directions in a 3D environment. The obtained feasible disassembly sequences can be used as solutions to support our developed Particle Swarm Optimisation (PSO)-based selective disassembly planning method to search optimised selective disassembly sequence for Liquid Crystal Display (LCD) televisions.

A green assembly sequence planning model with a closed-loop assembly and disassembly sequence planning using a particle swarm optimization method

In a green product life cycle, it is necessary to determine how to disassemble a product before the product is planned to be assembled. In this research, a green assembly sequence planning model is developed. A closed-loop assembly sequence planning model is presented by integrating assembly and disassembly sequence planning models. For an assembled product, an assembly sequence planning model is required for assembling the product at the start, while a disassembly sequence planning model is performed for disassembling the product at the end. In typical assembly and disassembly sequence planning approaches, the two sequences are independently planned and evaluated. In this paper, a closed-loop model is presented to concurrently generate and evaluate the assembly and disassembly sequences. First, a graph-based model is presented for representing the feasible assembly sequences and disassembly sequences. Next, a particle swarm optimization (PSO) method with a new encoding scheme is presented. In the PSO method, the assembly and disassembly sequences can be simultaneously represented and evaluated with an objective of minimizing the total of assembly costs and disassembly costs. The test results show that the presented method is feasible and efficient for solving the integrated assembly and disassembly sequence planning problem. An example product is illustrated and discussed.

A multiple objective tabu search approach for end-of-life product disassembly

This paper addresses the disassembly-to-order (DTO) and the disassembly sequence planning (DSP) problems and employs a multiple objective tabu search (MOTS) algorithm to solve them. The focus of the study is on the disassembly operations of end-of-life (EOL) products taken back from their last users (owners). The proposed approach aims at disassembling the EOL products for reusing, recycling, storing and properly disposing them in an environmentally benign manner. Thus, the model controls and restricts the environmental damage while increasing the value captured from the EOL products. These goals are achieved in an economically viable manner. The proposed model employs two independent modules, namely, the DTO module and the DSP module. The DTO module embodies multiple objectives and provides various options for the number of items to be disassembled from each EOL product for resale, recycling, storage and proper disposal, along with the numbers and types of EOL products to be taken back. The module considers both environmental and financial objectives while meeting the demand expectations. The DSP module provides multiple feasible disassembly sequences for the EOL products. The module considers and preserves the precedence relationships among the items while fulfilling multiple objectives.

분해우선작업을 가지는 페트리 넷 기반의 분해순서계획모델

This paper presents a Petri Net (PN) based disassembly sequence planning model with precedence operations. All feasible disassembly sequences are generated by a disassembly tree and a disassembly sequence is determined using the disassembly precedence and disassembly value matrix, The precedence of disassembly operations is determined through a disassembly tree and the value of disassembly is induced by economic analysis in the end-of-life phase. To solve the disassembly sequence planning model with precedence operations, a heuristic algorithm based on PNs is developed. The developed algorithm generates and searches a partial reachability graph to arrive at an optimal or near-optimal disassembly sequence based on the firing sequence of transitions of the PN model. A refrigerator is shown as an example to demonstrate the effectiveness of proposed model.

Optimal disassembly sequencing strategy using constraint programming approach

PurposeThe purpose of this paper is to propose a framework to identify all the feasible disassembly sequences for a multi‐component product and to find an optimal disassembly sequence, according to specific criteria such as cost, duration, profit, etc.Design/methodology/approachTaking into account topological and geometrical constraints of a product structure, an AND/OR disassembly graph is built. Each graph node represents a feasible subassembly. Two nodes i and j are connected by an arc (i, j), called a transition, if the subassembly j can be obtained from the subassembly i by removing one or several connectors. Constraint programming approach is used to generate the feasible subassemblies and related transitions.FindingsIf a cost zij is incurred to perform a transition (i, j), an optimal disassembly sequence can be generated for a given subassembly, using the shortest path algorithm or a linear programming model.Research limitations/implicationsThe proposed approach performs very well compared to other approaches published in the literature, even when applied to products requiring parallel disassembly and including a large number of parts.Practical implicationsThis approach has been successfully applied to assess the wheelchair maintainability at the design stage and will be implemented in CAD systems. One other application, regarding the disassembly process and total revenue maximization for product recycling, is now under consideration.Originality/valueApplying constraint programming to efficiently generate the set of the feasible subassemblies constitutes the main contribution in this paper. This process is the hardest step in the disassembly sequencing problem.

Disassembly sequence generation in recycling based on parts accessibility and end-of-life strategy

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 C++ is developed to generate the ODS. The disassembly of a C-clamp is used as a trial example.

Research on the selectable disassembly strategy of mechanical parts based on the generalized CAD model

Disassembly has gained much attention due to the growing concerns of material resources, energy conservation, and environmental conscious. The process of disassembly attempts to breakup a product into several pieces, with the expectation that the pieces together have a net value greater than the discarded product. In analyzing these aspects, one needs to determine all feasible ways to disassemble a product. This is especially true for the complex products like automobile, aircraft, etc. Most researchers took the algorithm of complete-disassembly planning to design for disassembly, although the feasible disassembly sequence can be obtained, parts of a assembled entity should be removed totally. And the required S (refers to disassembly sequence) could be gained through the proper analysis and evaluation; however, there are so many difficulties in this process and it is hard to obtain the optimum solution, especially when there are many parts in assembled body (such as automotive product). Therefore, it is very necessary to research the selectable disassembly algorithm of mechanical parts. This paper puts forward an algorithm on the selectable disassembly strategy of mechanical parts based on disassembly wave concept. It is comparatively easy and efficient to search, and get the optimal selectable disassembly sequence of mechanical parts with less amount of computing. It is so significant for all the steps of maintaining, recycling and discarding.

Disassembly sequencing for maintenance: A survey

This paper surveys the disassembly sequencing problems in which used or end-of-life products are disassembled into basic parts and components, especially due to repair and maintenance. Disassembly theory is applied to complex products such as mechanical, electromechanical and electronic appliances. Here, the disassembly sequencing includes feasible disassembly sequence generation and sequence optimization. Also, product representation issues are included for feasible disassembly sequence generation. This paper covers a state-of-the-art review on assembly/disassembly planning that can be used for disassembly sequencing for maintenance and gives a broad view of disassembly planning for maintenance and a basis for disassembly related research.

Structure representation for concurrent analysis of product assembly and disassembly

Abstract This paper presents a simple and novel structure representation supporting the assembly and disassembly planning of electromechanical products. The proposed Relationship Matrix derived from a directed graph represents both the information of the component connectivity and the layout precedence of functional elements. The feasible assembly and disassembly sequences and the minimum service steps for the malfunction component can be easily derived with the corresponding inference rules. The structure representation and the inference kernel can be readily applied to future concurrent design review for assemblability, serviceability, and recyclability. A prototype software tool is introduced to demonstrate the application of the proposed scheme.

Ant colony optimization for disassembly sequencing with multiple objectives

Product disassembly takes place in remanufacturing, recycling, and disposal. The disassembly line is the best choice for automated disassembly, so it is essential that it be designed and balanced to work efficiently. The multi-objective disassembly line balancing problem seeks to find a disassembly sequence which provides a feasible disassembly sequence, minimizes the number of workstations, minimizes idle time, balances the line (ensures similar idle times at each workstation), as well as addressing other disassembly-specific concerns. However, finding the optimal balance is computationally intensive due to exponential growth, with exhaustive search quickly becoming prohibitively large. In this paper, an ant colony optimization metaheuristic is presented for obtaining optimal or near-optimal solutions to the disassembly line balancing problem. Examples are considered to illustrate implementation of the methodology. Conclusions drawn include the consistent generation of near-optimal solutions, the ability to preserve precedence, the superior speed of the metaheuristic, and its practicality due to its ease of implementation.

Integrated approach for disassembly processes generation and recycling evaluation of an end-of-life product

An integrated approach for noble recycling is presented that puts forward the functional value of products and components. In a first step, the approach determines all feasible automatic disassembly sequences and in a second step all applicable recycling activities. This allows one to determine the most appropriate recycling process for an end-of-life product considering concurrent recycling techniques. The feasible automatic disassembly sequences are established by simulation in a virtual environment. The required generic disassembly product model, as well as the generic disassembly activity model, is presented by means of static and dynamic object-oriented diagrams. The recycling evaluation establishes an efficient solution responding to economic and ecological decision criteria. It is calculated applying a Goal-Programming approach transforming the multi-objective linear problem into a monocriteria linear program. The techno-economic decision model applied is Linear Activity Analysis. It allows one to integrate the generated disassembly processes based on single disassembly activities as well as other recycling techniques.

A scatter search approach to the optimum disassembly sequence problem

One of the most difficult problems faced by OR researchers in the reverse logistics field consists in determining an efficient disassembly sequence for a product at its end of life. In this paper, a scatter search (SS) metaheuristic is presented aiming to deal with the optimum disassembly sequence problem for the case of complex products with sequence-dependent disassembly costs, and assuming that only one component can be released at each time. The algorithm was tested over a set of 48 products consisting of 25, 50, 75 and 100 right-angled parallelepiped components, connected by different kinds of joints. A feasible disassembly sequence, consisting on the reverse of the assembly sequence, is always usable. Comparing by using some statistical analysis the costs of the sequence proposed by the SS algorithm with those corresponding to the reverse order, efficiency of the metaheuristic is shown up.

Computer-Aided Design for Product De- and Remanufacture

Abstract Increasingly, designers are asked to consider additional types of requirements, including the environmental impact of their designs during the product's lifetime and after its useful life. Two of these types of requirements are investigated in this article. Demanufacturing is the process of dismantling a product and disposing or recycling of components, modules, or materials. Product reuse retains a greater portion of its value and often requires remanufacturing, the refurbishment of a product or product modules. In this article, requirements for CAD representations to support de-and remanufacture assessments at multiple stages in the design process are identified. Information requirements are classified into categories according to the difficulty in extracting the information from assembly-based CAD representations. Information not obtainable from CAD representations is noted. Methods for querying CAD systems to extract significant amounts of this information are presented. Methods for supporting limited product redesign are enabled by a new fastener representation. These methods have been incorporated into the prototypical CAD system CODA. This work is applied to the design for de- and remanufacture of an automotive instrument cluster. It is shown that feasible disassembly sequences can be generated, ideal parts can be recognized, and de- and remanufacturing assessments provided.

Optimal Disassembly Sequence Using Genetic Algorithms Considering Economic and Environmental Aspects

In this paper, a genetic algorithm (GA)-based approach for an optimal disassembly sequence considering economic and environmental aspects is presented. All feasible disassembly sequences are generated by a disassembly tree or an AND/OR graph. Using the disassembly precedence and the disassembly value matrix, a disassembly sequence is optimised. The precedence of disassembly is determined through a disassembly tree or an AND/OR graph and the value of disassembly is induced by considering both economic and environmental aspects in the disassembly, recycling, and disposal phases. Economic and environmental factors can be compared by the same measure through converting environmental factors into economic cost. To solve the disassembly sequence problem, a heuristic algorithm based on GAs is developed. The proposed GA can search for and dynamically explore the disassembly node through the highest disassembly value, keeping their precedence in order to identify an optimal disassembly sequence. It can also help to explore the search space, and an optimal solution can be obtained by applying the optimisation criteria. A refrigerator is used as an example to illustrate the procedure.

A disassembly planning software system for the optimization of recycling processes

This paper describes the methods and algorithms adopted in a software system for the generation of optimized disassembly plans to be used in recycling of end-of-life goods. Three aspects of the system are particularly emphasized: the integration with CAD; the capability to automatically detect the subassemblies of the product; and the capability to auto matically generate all the feasible disassembly sequences. The selection of the best disassembly plan is made on the basis of the maximum profit achievable from the recycling of components, calculated according to the information contained in a database and concerning the market, the available tools, etc. A meaningful example of application is reported and discussed in detail, analysing the system performance in different situations, e.g. different market conditions, different deterioration of the good, application of different kinds of disassembly operations.